Documentation
¶
Overview ¶
Package gosnowflake is a pure Go Snowflake driver for the database/sql package.
Clients can use the database/sql package directly. For example:
import ( "database/sql" _ "github.com/snowflakedb/gosnowflake" "log" ) func main() { db, err := sql.Open("snowflake", "user:password@my_organization-my_account/mydb") if err != nil { log.Fatal(err) } defer db.Close() ... }
Connection String ¶
Use the Open() function to create a database handle with connection parameters:
db, err := sql.Open("snowflake", "<connection string>")
The Go Snowflake Driver supports the following connection syntaxes (or data source name (DSN) formats):
- username[:password]@<account_identifier>/dbname/schemaname[?param1=value&...¶mN=valueN]
- username[:password]@<account_identifier>/dbname[?param1=value&...¶mN=valueN]
- username[:password]@hostname:port/dbname/schemaname?account=<account_identifier>[¶m1=value&...¶mN=valueN]
where all parameters must be escaped or use Config and DSN to construct a DSN string.
For information about account identifiers, see the Snowflake documentation (https://docs.snowflake.com/en/user-guide/admin-account-identifier.html).
The following example opens a database handle with the Snowflake account named "my_account" under the organization named "my_organization", where the username is "jsmith", password is "mypassword", database is "mydb", schema is "testschema", and warehouse is "mywh":
db, err := sql.Open("snowflake", "jsmith:mypassword@my_organization-my_account/mydb/testschema?warehouse=mywh")
Connection Parameters ¶
The connection string (DSN) can contain both connection parameters (described below) and session parameters (https://docs.snowflake.com/en/sql-reference/parameters.html).
The following connection parameters are supported:
account <string>: Specifies your Snowflake account, where "<string>" is the account identifier assigned to your account by Snowflake. For information about account identifiers, see the Snowflake documentation (https://docs.snowflake.com/en/user-guide/admin-account-identifier.html).
If you are using a global URL, then append the connection group and ".global" (e.g. "<account_identifier>-<connection_group>.global"). The account identifier and the connection group are separated by a dash ("-"), as shown above.
This parameter is optional if your account identifier is specified after the "@" character in the connection string.
region <string>: DEPRECATED. You may specify a region, such as "eu-central-1", with this parameter. However, since this parameter is deprecated, it is best to specify the region as part of the account parameter. For details, see the description of the account parameter.
database: Specifies the database to use by default in the client session (can be changed after login).
schema: Specifies the database schema to use by default in the client session (can be changed after login).
warehouse: Specifies the virtual warehouse to use by default for queries, loading, etc. in the client session (can be changed after login).
role: Specifies the role to use by default for accessing Snowflake objects in the client session (can be changed after login).
passcode: Specifies the passcode provided by Duo when using multi-factor authentication (MFA) for login.
passcodeInPassword: false by default. Set to true if the MFA passcode is embedded in the login password. Appends the MFA passcode to the end of the password.
loginTimeout: Specifies the timeout, in seconds, for login. The default is 60 seconds. The login request gives up after the timeout length if the HTTP response is success.
requestTimeout: Specifies the timeout, in seconds, for a query to complete. 0 (zero) specifies that the driver should wait indefinitely. The default is 0 seconds. The query request gives up after the timeout length if the HTTP response is success.
authenticator: Specifies the authenticator to use for authenticating user credentials:
To use the internal Snowflake authenticator, specify snowflake (Default).
To authenticate through Okta, specify https://<okta_account_name>.okta.com (URL prefix for Okta).
To authenticate using your IDP via a browser, specify externalbrowser.
To authenticate via OAuth, specify oauth and provide an OAuth Access Token (see the token parameter below).
application: Identifies your application to Snowflake Support.
insecureMode: false by default. Set to true to bypass the Online Certificate Status Protocol (OCSP) certificate revocation check. IMPORTANT: Change the default value for testing or emergency situations only.
token: a token that can be used to authenticate. Should be used in conjunction with the "oauth" authenticator.
client_session_keep_alive: Set to true have a heartbeat in the background every hour to keep the connection alive such that the connection session will never expire. Care should be taken in using this option as it opens up the access forever as long as the process is alive.
ocspFailOpen: true by default. Set to false to make OCSP check fail closed mode.
validateDefaultParameters: true by default. Set to false to disable checks on existence and privileges check for Database, Schema, Warehouse and Role when setting up the connection
tracing: Specifies the logging level to be used. Set to error by default. Valid values are trace, debug, info, print, warning, error, fatal, panic.
disableQueryContextCache: disables parsing of query context returned from server and resending it to server as well. Default value is false.
clientConfigFile: specifies the location of the client configuration json file. In this file you can configure Easy Logging feature.
All other parameters are interpreted as session parameters (https://docs.snowflake.com/en/sql-reference/parameters.html). For example, the TIMESTAMP_OUTPUT_FORMAT session parameter can be set by adding:
...&TIMESTAMP_OUTPUT_FORMAT=MM-DD-YYYY...
A complete connection string looks similar to the following:
my_user_name:my_password@ac123456/my_database/my_schema?my_warehouse=inventory_warehouse&role=my_user_role&DATE_OUTPUT_FORMAT=YYYY-MM-DD ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ connection connection session parameter parameter parameter
Session-level parameters can also be set by using the SQL command "ALTER SESSION" (https://docs.snowflake.com/en/sql-reference/sql/alter-session.html).
Alternatively, use OpenWithConfig() function to create a database handle with the specified Config.
Proxy ¶
The Go Snowflake Driver honors the environment variables HTTP_PROXY, HTTPS_PROXY and NO_PROXY for the forward proxy setting.
NO_PROXY specifies which hostname endings should be allowed to bypass the proxy server, e.g. no_proxy=.amazonaws.com means that Amazon S3 access does not need to go through the proxy.
NO_PROXY does not support wildcards. Each value specified should be one of the following:
The end of a hostname (or a complete hostname), for example: ".amazonaws.com" or "xy12345.snowflakecomputing.com".
An IP address, for example "192.196.1.15".
If more than one value is specified, values should be separated by commas, for example:
no_proxy=localhost,.my_company.com,xy12345.snowflakecomputing.com,192.168.1.15,192.168.1.16
Logging ¶
By default, the driver's builtin logger is exposing logrus's FieldLogger and default at INFO level. Users can use SetLogger in driver.go to set a customized logger for gosnowflake package.
In order to enable debug logging for the driver, user could use SetLogLevel("debug") in SFLogger interface as shown in demo code at cmd/logger.go. To redirect the logs SFlogger.SetOutput method could do the work.
Query tag ¶
A custom query tag can be set in the context. Each query run with this context will include the custom query tag as metadata that will appear in the Query Tag column in the Query History log. For example:
queryTag := "my custom query tag" ctxWithQueryTag := WithQueryTag(ctx, queryTag) rows, err := db.QueryContext(ctxWithQueryTag, query)
Query request ID ¶
A specific query request ID can be set in the context and will be passed through in place of the default randomized request ID. For example:
requestID := ParseUUID("6ba7b812-9dad-11d1-80b4-00c04fd430c8") ctxWithID := WithRequestID(ctx, requestID) rows, err := db.QueryContext(ctxWithID, query)
Last query ID ¶
If you need query ID for your query you have to use raw connection.
For queries: ```
err := conn.Raw(func(x any) error { stmt, err := x.(driver.ConnPrepareContext).PrepareContext(ctx, "SELECT 1") rows, err := stmt.(driver.StmtQueryContext).QueryContext(ctx, nil) rows.(SnowflakeRows).GetQueryID() stmt.(SnowflakeStmt).GetQueryID() return nil }
```
For execs: ```
err := conn.Raw(func(x any) error { stmt, err := x.(driver.ConnPrepareContext).PrepareContext(ctx, "INSERT INTO TestStatementQueryIdForExecs VALUES (1)") result, err := stmt.(driver.StmtExecContext).ExecContext(ctx, nil) result.(SnowflakeResult).GetQueryID() stmt.(SnowflakeStmt).GetQueryID() return nil }
```
Fetch Results by Query ID ¶
The result of your query can be retrieved by setting the query ID in the WithFetchResultByID context. ```
// Get the query ID using raw connection as mentioned above: err := conn.Raw(func(x any) error { rows1, err = x.(driver.QueryerContext).QueryContext(ctx, "SELECT 1", nil) queryID = rows1.(sf.SnowflakeRows).GetQueryID() return nil } // Update the Context object to specify the query ID fetchResultByIDCtx = sf.WithFetchResultByID(ctx, queryID) // Execute an empty string query rows2, err := db.QueryContext(fetchResultByIDCtx, "") // Retrieve the results as usual for rows2.Next() { err = rows2.Scan(...) ... }
```
Canceling Query by CtrlC ¶
From 0.5.0, a signal handling responsibility has moved to the applications. If you want to cancel a query/command by Ctrl+C, add a os.Interrupt trap in context to execute methods that can take the context parameter (e.g. QueryContext, ExecContext).
// handle interrupt signal ctx, cancel := context.WithCancel(context.Background()) c := make(chan os.Signal, 1) signal.Notify(c, os.Interrupt) defer func() { signal.Stop(c) }() go func() { select { case <-c: cancel() case <-ctx.Done(): } }() ... (connection) // execute a query rows, err := db.QueryContext(ctx, query) ... (Ctrl+C to cancel the query)
See cmd/selectmany.go for the full example.
Supported Data Types ¶
The Go Snowflake Driver now supports the Arrow data format for data transfers between Snowflake and the Golang client. The Arrow data format avoids extra conversions between binary and textual representations of the data. The Arrow data format can improve performance and reduce memory consumption in clients.
Snowflake continues to support the JSON data format.
The data format is controlled by the session-level parameter GO_QUERY_RESULT_FORMAT. To use JSON format, execute:
ALTER SESSION SET GO_QUERY_RESULT_FORMAT = 'JSON';
The valid values for the parameter are:
- ARROW (default)
- JSON
If the user attempts to set the parameter to an invalid value, an error is returned.
The parameter name and the parameter value are case-insensitive.
This parameter can be set only at the session level.
Usage notes:
The Arrow data format reduces rounding errors in floating point numbers. You might see slightly different values for floating point numbers when using Arrow format than when using JSON format. In order to take advantage of the increased precision, you must pass in the context.Context object provided by the WithHigherPrecision function when querying.
Traditionally, the rows.Scan() method returned a string when a variable of types interface was passed in. Turning on the flag ENABLE_HIGHER_PRECISION via WithHigherPrecision will return the natural, expected data type as well.
For some numeric data types, the driver can retrieve larger values when using the Arrow format than when using the JSON format. For example, using Arrow format allows the full range of SQL NUMERIC(38,0) values to be retrieved, while using JSON format allows only values in the range supported by the Golang int64 data type.
Users should ensure that Golang variables are declared using the appropriate data type for the full range of values contained in the column. For an example, see below.
When using the Arrow format, the driver supports more Golang data types and more ways to convert SQL values to those Golang data types. The table below lists the supported Snowflake SQL data types and the corresponding Golang data types. The columns are:
The SQL data type.
The default Golang data type that is returned when you use snowflakeRows.Scan() to read data from Arrow data format via an interface{}.
The possible Golang data types that can be returned when you use snowflakeRows.Scan() to read data from Arrow data format directly.
The default Golang data type that is returned when you use snowflakeRows.Scan() to read data from JSON data format via an interface{}. (All returned values are strings.)
The standard Golang data type that is returned when you use snowflakeRows.Scan() to read data from JSON data format directly.
Go Data Types for Scan() =================================================================================================================== | ARROW | JSON =================================================================================================================== SQL Data Type | Default Go Data Type | Supported Go Data | Default Go Data Type | Supported Go Data | for Scan() interface{} | Types for Scan() | for Scan() interface{} | Types for Scan() =================================================================================================================== BOOLEAN | bool | string | bool ------------------------------------------------------------------------------------------------------------------- VARCHAR | string | string ------------------------------------------------------------------------------------------------------------------- DOUBLE | float32, float64 [1] , [2] | string | float32, float64 ------------------------------------------------------------------------------------------------------------------- INTEGER that | int, int8, int16, int32, int64 | string | int, int8, int16, fits in int64 | [1] , [2] | | int32, int64 ------------------------------------------------------------------------------------------------------------------- INTEGER that doesn't | int, int8, int16, int32, int64, *big.Int | string | error fit in int64 | [1] , [2] , [3] , [4] | ------------------------------------------------------------------------------------------------------------------- NUMBER(P, S) | float32, float64, *big.Float | string | float32, float64 where S > 0 | [1] , [2] , [3] , [5] | ------------------------------------------------------------------------------------------------------------------- DATE | time.Time | string | time.Time ------------------------------------------------------------------------------------------------------------------- TIME | time.Time | string | time.Time ------------------------------------------------------------------------------------------------------------------- TIMESTAMP_LTZ | time.Time | string | time.Time ------------------------------------------------------------------------------------------------------------------- TIMESTAMP_NTZ | time.Time | string | time.Time ------------------------------------------------------------------------------------------------------------------- TIMESTAMP_TZ | time.Time | string | time.Time ------------------------------------------------------------------------------------------------------------------- BINARY | []byte | string | []byte ------------------------------------------------------------------------------------------------------------------- ARRAY | string | string ------------------------------------------------------------------------------------------------------------------- OBJECT | string | string ------------------------------------------------------------------------------------------------------------------- VARIANT | string | string
[1] Converting from a higher precision data type to a lower precision data type via the snowflakeRows.Scan() method can lose low bits (lose precision), lose high bits (completely change the value), or result in error.
[2] Attempting to convert from a higher precision data type to a lower precision data type via interface{} causes an error.
[3] Higher precision data types like *big.Int and *big.Float can be accessed by querying with a context returned by WithHigherPrecision().
[4] You cannot directly Scan() into the alternative data types via snowflakeRows.Scan(), but can convert to those data types by using .Int64()/.String()/.Uint64() methods. For an example, see below.
[5] You cannot directly Scan() into the alternative data types via snowflakeRows.Scan(), but can convert to those data types by using .Float32()/.String()/.Float64() methods. For an example, see below.
Note: SQL NULL values are converted to Golang nil values, and vice-versa.
The following example shows how to retrieve very large values using the math/big package. This example retrieves a large INTEGER value to an interface and then extracts a big.Int value from that interface. If the value fits into an int64, then the code also copies the value to a variable of type int64. Note that a context that enables higher precision must be passed in with the query.
import "context" import "math/big" ... var my_interface interface{} var my_big_int_pointer *big.Int var my_int64 int64 var rows snowflakeRows ... rows = db.QueryContext(WithHigherPrecision(context.Background), <query>) rows.Scan(&my_interface) my_big_int_pointer, ok = my_interface.(*big.Int) if my_big_int_pointer.IsInt64() { my_int64 = my_big_int_pointer.Int64() }
If the variable named "rows" is known to contain a big.Int, then you can use the following instead of scanning into an interface and then converting to a big.Int:
rows.Scan(&my_big_int_pointer)
If the variable named "rows" contains a big.Int, then each of the following fails:
rows.Scan(&my_int64) my_int64, _ = my_interface.(int64)
Similar code and rules also apply to big.Float values.
If you are not sure what data type will be returned, you can use code similar to the following to check the data type of the returned value:
// Create variables into which you can scan the returned values. var i64 int64 var bigIntPtr *big.Int for rows.Next() { // Get the data type info. column_types, err := rows.ColumnTypes() if err != nil { log.Fatalf("ERROR: ColumnTypes() failed. err: %v", err) } // The data type of the zeroeth column in the row. column_type := column_types[0].ScanType() // Choose the appropriate variable based on the data type. switch column_type { case reflect.TypeOf(i64): err = rows.Scan(&i64) fmt.Println("INFO: retrieved int64 value:") fmt.Println(i64) case reflect.TypeOf(bigIntPtr): err = rows.Scan(&bigIntPtr) fmt.Println("INFO: retrieved bigIntPtr value:") fmt.Println(bigIntPtr) } }
## Arrow batches
You can retrieve data in a columnar format similar to the format a server returns. You must use `WithArrowBatches` context, similar to the following:
var rows driver.Rows err = conn.Raw(func(x interface{}) error { rows, err = x.(driver.QueryerContext).QueryContext(ctx, query, nil) return err }) ... batches, err := rows.(sf.SnowflakeRows).GetArrowBatches() ... // use Arrow records
Limitations:
1. For some queries Snowflake may decide to return data in JSON format (examples: `SHOW PARAMETERS` or `ls @stage`). You cannot use JSON with Arrow batches context. 2. Snowflake handles timestamps in a range which is higher than available space in Arrow timestamp type. Because of that special treatment should be used (see below).
### Handling timestamps in Arrow batches
Snowflake returns timestamps natively (from backend to driver) in multiple formats. The Arrow timestamp is an 8-byte data type, which is insufficient to handle the larger date and time ranges used by Snowflake. Also, Snowflake supports 0-9 (nanosecond) digit precision for seconds, while Arrow supports only 3 (millisecond), 6 (microsecond), an 9 (nanosecond) precision. Consequently, Snowflake uses a custom timestamp format in Arrow, which differs on timestamp type and precision.
If you want to use timestamps in Arrow batches, you have two options:
- The Go driver can reduce timestamp struct into simple Arrow Timestamp, if you set `WithArrowBatchesTimestampOption` to nanosecond, microsecond, millisecond or second. For nanosecond, some timestamp values might not fit into Arrow timestamp. E.g after year 2262 or before 1677.
- You can use native Snowflake values. In that case you will receive complex structs as described above. To transform Snowflake values into the Golang time.Time struct you can use `ArrowSnowflakeTimestampToTime`. To enable this feature, you must use `WithArrowBatchesTimestampOption` context with value set to`UseOriginalTimestamp`.
### Invalid UTF-8 characters in Arrow batches Snowflake previously allowed users to upload data with invalid UTF-8 characters. Consequently, Arrow records containing string columns in Snowflake could include these invalid UTF-8 characters. However, according to the Arrow specifications (https://arrow.apache.org/docs/cpp/api/datatype.html and https://github.com/apache/arrow/blob/a03d957b5b8d0425f9d5b6c98b6ee1efa56a1248/go/arrow/datatype.go#L73-L74), Arrow string columns should only contain UTF-8 characters.
To address this issue and prevent potential downstream disruptions, the context `enableArrowBatchesUtf8Validation`, is introduced. When enabled, this feature iterates through all values in string columns, identifying and replacing any invalid characters with `�`. This ensures that Arrow records conform to the UTF-8 standards, preventing validation failures in downstream services like the Rust Arrow library that impose strict validation checks.
### WithHigherPrecision in Arrow batches To preserve BigDecimal values within Arrow batches, use `WithHigherPrecision`. This offers two main benefits: it helps avoid precision loss and defers the conversion to upstream services. Alternatively, without this setting, all non-zero scale numbers will be converted to float64, potentially resulting in loss of precision. Zero-scale numbers (DECIMAL256, DECIMAL128) will be converted to int64, which could lead to overflow.
Binding Parameters ¶
Binding allows a SQL statement to use a value that is stored in a Golang variable.
Without binding, a SQL statement specifies values by specifying literals inside the statement. For example, the following statement uses the literal value “42“ in an UPDATE statement:
_, err = db.Exec("UPDATE table1 SET integer_column = 42 WHERE ID = 1000")
With binding, you can execute a SQL statement that uses a value that is inside a variable. For example:
var my_integer_variable int = 42 _, err = db.Exec("UPDATE table1 SET integer_column = ? WHERE ID = 1000", my_integer_variable)
The “?“ inside the “VALUES“ clause specifies that the SQL statement uses the value from a variable.
Binding data that involves time zones can require special handling. For details, see the section titled "Timestamps with Time Zones".
Version 1.6.23 (and later) of the driver takes advantage of sql.Null types which enables the proper handling of null parameters inside function calls, i.e.:
rows, err := db.Query("SELECT * FROM TABLE(SOMEFUNCTION(?))", sql.NullBool{})
The timestamp nullability had to be achieved by wrapping the sql.NullTime type as the Snowflake provides several date and time types which are mapped to single Go time.Time type:
rows, err := db.Query("SELECT * FROM TABLE(SOMEFUNCTION(?))", sf.TypedNullTime{sql.NullTime{}, sf.TimestampLTZType})
Binding Parameters to Array Variables ¶
Version 1.3.9 (and later) of the Go Snowflake Driver supports the ability to bind an array variable to a parameter in a SQL INSERT statement. You can use this technique to insert multiple rows in a single batch.
As an example, the following code inserts rows into a table that contains integer, float, boolean, and string columns. The example binds arrays to the parameters in the INSERT statement.
// Create a table containing an integer, float, boolean, and string column. _, err = db.Exec("create or replace table my_table(c1 int, c2 float, c3 boolean, c4 string)") ... // Define the arrays containing the data to insert. intArray := []int{1, 2, 3} fltArray := []float64{0.1, 2.34, 5.678} boolArray := []bool{true, false, true} strArray := []string{"test1", "test2", "test3"} ... // Insert the data from the arrays and wrap in an Array() function into the table. _, err = db.Exec("insert into my_table values (?, ?, ?, ?)", Array(&intArray), Array(&fltArray), Array(&boolArray), Array(&strArray))
If the array contains SQL NULL values, use slice []interface{}, which allows Golang nil values. This feature is available in version 1.6.12 (and later) of the driver. For example,
// Define the arrays containing the data to insert. strArray := make([]interface{}, 3) strArray[0] = "test1" strArray[1] = "test2" strArray[2] = nil // This line is optional as nil is the default value. ... // Create a table and insert the data from the array as shown above. _, err = db.Exec("create or replace table my_table(c1 string)") _, err = db.Exec("insert into my_table values (?)", Array(&strArray)) ... // Use sql.NullString to fetch the string column that contains NULL values. var s sql.NullString rows, _ := db.Query("select * from my_table") for rows.Next() { err := rows.Scan(&s) if err != nil { log.Fatalf("Failed to scan. err: %v", err) } if s.Valid { fmt.Println("Retrieved value:", s.String) } else { fmt.Println("Retrieved value: NULL") } }
For slices []interface{} containing time.Time values, a binding parameter flag is required for the preceding array variable in the Array() function. This feature is available in version 1.6.13 (and later) of the driver. For example,
_, err = db.Exec("create or replace table my_table(c1 timestamp_ntz, c2 timestamp_ltz)") _, err = db.Exec("insert into my_table values (?,?)", Array(&ntzArray, sf.TimestampNTZType), Array(<zArray, sf.TimestampLTZType))
Note: For alternative ways to load data into the Snowflake database (including bulk loading using the COPY command), see Loading Data into Snowflake (https://docs.snowflake.com/en/user-guide-data-load.html).
Batch Inserts and Binding Parameters ¶
When you use array binding to insert a large number of values, the driver can improve performance by streaming the data (without creating files on the local machine) to a temporary stage for ingestion. The driver automatically does this when the number of values exceeds a threshold (no changes are needed to user code).
In order for the driver to send the data to a temporary stage, the user must have the following privilege on the schema:
CREATE STAGE
If the user does not have this privilege, the driver falls back to sending the data with the query to the Snowflake database.
In addition, the current database and schema for the session must be set. If these are not set, the CREATE TEMPORARY STAGE command executed by the driver can fail with the following error:
CREATE TEMPORARY STAGE SYSTEM$BIND file_format=(type=csv field_optionally_enclosed_by='"') Cannot perform CREATE STAGE. This session does not have a current schema. Call 'USE SCHEMA', or use a qualified name.
For alternative ways to load data into the Snowflake database (including bulk loading using the COPY command), see Loading Data into Snowflake (https://docs.snowflake.com/en/user-guide-data-load.html).
Binding a Parameter to a Time Type ¶
Go's database/sql package supports the ability to bind a parameter in a SQL statement to a time.Time variable. However, when the client binds data to send to the server, the driver cannot determine the correct Snowflake date/timestamp data type to associate with the binding parameter. For example:
dbt.mustExec("CREATE OR REPLACE TABLE tztest (id int, ntz, timestamp_ntz, ltz timestamp_ltz)") // ... stmt, err :=dbt.db.Prepare("INSERT INTO tztest(id,ntz,ltz) VALUES(1, ?, ?)") // ... tmValue time.Now() // ... Is tmValue a TIMESTAMP_NTZ or TIMESTAMP_LTZ? _, err = stmt.Exec(tmValue, tmValue)
To resolve this issue, a binding parameter flag is introduced that associates any subsequent time.Time type to the DATE, TIME, TIMESTAMP_LTZ, TIMESTAMP_NTZ or BINARY data type. The above example could be rewritten as follows:
import ( sf "github.com/snowflakedb/gosnowflake" ) dbt.mustExec("CREATE OR REPLACE TABLE tztest (id int, ntz, timestamp_ntz, ltz timestamp_ltz)") // ... stmt, err :=dbt.db.Prepare("INSERT INTO tztest(id,ntz,ltz) VALUES(1, ?, ?)") // ... tmValue time.Now() // ... _, err = stmt.Exec(sf.DataTypeTimestampNtz, tmValue, sf.DataTypeTimestampLtz, tmValue)
Timestamps with Time Zones ¶
The driver fetches TIMESTAMP_TZ (timestamp with time zone) data using the offset-based Location types, which represent a collection of time offsets in use in a geographical area, such as CET (Central European Time) or UTC (Coordinated Universal Time). The offset-based Location data is generated and cached when a Go Snowflake Driver application starts, and if the given offset is not in the cache, it is generated dynamically.
Currently, Snowflake does not support the name-based Location types (e.g. "America/Los_Angeles").
For more information about Location types, see the Go documentation for https://golang.org/pkg/time/#Location.
Binary Data ¶
Internally, this feature leverages the []byte data type. As a result, BINARY data cannot be bound without the binding parameter flag. In the following example, sf is an alias for the gosnowflake package:
var b = []byte{0x01, 0x02, 0x03} _, err = stmt.Exec(sf.DataTypeBinary, b)
Maximum Number of Result Set Chunk Downloader ¶
The driver directly downloads a result set from the cloud storage if the size is large. It is required to shift workloads from the Snowflake database to the clients for scale. The download takes place by goroutine named "Chunk Downloader" asynchronously so that the driver can fetch the next result set while the application can consume the current result set.
The application may change the number of result set chunk downloader if required. Note this does not help reduce memory footprint by itself. Consider Custom JSON Decoder.
import ( sf "github.com/snowflakedb/gosnowflake" ) sf.MaxChunkDownloadWorkers = 2
Custom JSON Decoder for Parsing Result Set (Experimental)
The application may have the driver use a custom JSON decoder that incrementally parses the result set as follows.
import ( sf "github.com/snowflakedb/gosnowflake" ) sf.CustomJSONDecoderEnabled = true ...
This option will reduce the memory footprint to half or even quarter, but it can significantly degrade the performance depending on the environment. The test cases running on Travis Ubuntu box show five times less memory footprint while four times slower. Be cautious when using the option.
JWT authentication ¶
The Go Snowflake Driver supports JWT (JSON Web Token) authentication.
To enable this feature, construct the DSN with fields "authenticator=SNOWFLAKE_JWT&privateKey=<your_private_key>", or using a Config structure specifying:
config := &Config{ ... Authenticator: AuthTypeJwt, PrivateKey: "<your_private_key_struct in *rsa.PrivateKey type>", }
The <your_private_key> should be a base64 URL encoded PKCS8 rsa private key string. One way to encode a byte slice to URL base 64 URL format is through the base64.URLEncoding.EncodeToString() function.
On the server side, you can alter the public key with the SQL command:
ALTER USER <your_user_name> SET RSA_PUBLIC_KEY='<your_public_key>';
The <your_public_key> should be a base64 Standard encoded PKI public key string. One way to encode a byte slice to base 64 Standard format is through the base64.StdEncoding.EncodeToString() function.
To generate the valid key pair, you can execute the following commands in the shell:
# generate 2048-bit pkcs8 encoded RSA private key openssl genpkey -algorithm RSA \ -pkeyopt rsa_keygen_bits:2048 \ -pkeyopt rsa_keygen_pubexp:65537 | \ openssl pkcs8 -topk8 -outform der > rsa-2048-private-key.p8 # extract 2048-bit PKI encoded RSA public key from the private key openssl pkey -pubout -inform der -outform der \ -in rsa-2048-private-key.p8 \ -out rsa-2048-public-key.spki
Note: As of February 2020, Golang's official library does not support passcode-encrypted PKCS8 private key. For security purposes, Snowflake highly recommends that you store the passcode-encrypted private key on the disk and decrypt the key in your application using a library you trust.
JWT tokens are recreated on each retry and they are valid (`exp` claim) for `jwtTimeout` seconds. Each retry timeout is configured by `jwtClientTimeout`. Retries are limited by total time of `loginTimeout`.
External browser authentication ¶
The driver allows to authenticate using the external browser.
When a connection is created, the driver will open the browser window and ask the user to sign in.
To enable this feature, construct the DSN with field "authenticator=EXTERNALBROWSER" or using a Config structure with following Authenticator specified:
config := &Config{ ... Authenticator: AuthTypeExternalBrowser, }
The external browser authentication implements timeout mechanism. This prevents the driver from hanging interminably when browser window was closed, or not responding.
Timeout defaults to 120s and can be changed through setting DSN field "externalBrowserTimeout=240" (time in seconds) or using a Config structure with following ExternalBrowserTimeout specified:
config := &Config{ ExternalBrowserTimeout: 240 * time.Second, // Requires time.Duration }
Executing Multiple Statements in One Call ¶
This feature is available in version 1.3.8 or later of the driver.
By default, Snowflake returns an error for queries issued with multiple statements. This restriction helps protect against SQL Injection attacks (https://en.wikipedia.org/wiki/SQL_injection).
The multi-statement feature allows users skip this restriction and execute multiple SQL statements through a single Golang function call. However, this opens up the possibility for SQL injection, so it should be used carefully. The risk can be reduced by specifying the exact number of statements to be executed, which makes it more difficult to inject a statement by appending it. More details are below.
The Go Snowflake Driver provides two functions that can execute multiple SQL statements in a single call:
- db.QueryContext(): This function is used to execute queries, such as SELECT statements, that return a result set.
- db.ExecContext(): This function is used to execute statements that don't return a result set (i.e. most DML and DDL statements).
To compose a multi-statement query, simply create a string that contains all the queries, separated by semicolons, in the order in which the statements should be executed.
To protect against SQL Injection attacks while using the multi-statement feature, pass a Context that specifies the number of statements in the string. For example:
import ( "context" "database/sql" ) var multi_statement_query = "SELECT c1 FROM t1; SELECT c2 FROM t2" var number_of_statements = 2 blank_context = context.Background() multi_statement_context, _ := WithMultiStatement(blank_context, number_of_statements) rows, err := db.QueryContext(multi_statement_context, multi_statement_query)
When multiple queries are executed by a single call to QueryContext(), multiple result sets are returned. After you process the first result set, get the next result set (for the next SQL statement) by calling NextResultSet().
The following pseudo-code shows how to process multiple result sets:
Execute the statement and get the result set(s): rows, err := db.QueryContext(ctx, multiStmtQuery) Retrieve the rows in the first query's result set: while rows.Next() { err = rows.Scan(&variable_1) if err != nil { t.Errorf("failed to scan: %#v", err) } ... } Retrieve the remaining result sets and the rows in them: while rows.NextResultSet() { while rows.Next() { ... } }
The function db.ExecContext() returns a single result, which is the sum of the number of rows changed by each individual statement. For example, if your multi-statement query executed two UPDATE statements, each of which updated 10 rows, then the result returned would be 20. Individual row counts for individual statements are not available.
The following code shows how to retrieve the result of a multi-statement query executed through db.ExecContext():
Execute the SQL statements: res, err := db.ExecContext(ctx, multiStmtQuery) Get the summed result and store it in the variable named count: count, err := res.RowsAffected()
Note: Because a multi-statement ExecContext() returns a single value, you cannot detect offsetting errors. For example, suppose you expected the return value to be 20 because you expected each UPDATE statement to update 10 rows. If one UPDATE statement updated 15 rows and the other UPDATE statement updated only 5 rows, the total would still be 20. You would see no indication that the UPDATES had not functioned as expected.
The ExecContext() function does not return an error if passed a query (e.g. a SELECT statement). However, it still returns only a single value, not a result set, so using it to execute queries (or a mix of queries and non-query statements) is impractical.
The QueryContext() function does not return an error if passed non-query statements (e.g. DML). The function returns a result set for each statement, whether or not the statement is a query. For each non-query statement, the result set contains a single row that contains a single column; the value is the number of rows changed by the statement.
If you want to execute a mix of query and non-query statements (e.g. a mix of SELECT and DML statements) in a multi-statement query, use QueryContext(). You can retrieve the result sets for the queries, and you can retrieve or ignore the row counts for the non-query statements.
Note: PUT statements are not supported for multi-statement queries.
If a SQL statement passed to ExecQuery() or QueryContext() fails to compile or execute, that statement is aborted, and subsequent statements are not executed. Any statements prior to the aborted statement are unaffected.
For example, if the statements below are run as one multi-statement query, the multi-statement query fails on the third statement, and an exception is thrown.
CREATE OR REPLACE TABLE test(n int); INSERT INTO TEST VALUES (1), (2); INSERT INTO TEST VALUES ('not_an_integer'); -- execution fails here INSERT INTO TEST VALUES (3);
If you then query the contents of the table named "test", the values 1 and 2 would be present.
When using the QueryContext() and ExecContext() functions, golang code can check for errors the usual way. For example:
rows, err := db.QueryContext(ctx, multiStmtQuery) if err != nil { Fatalf("failed to query multiple statements: %v", err) }
Preparing statements and using bind variables are also not supported for multi-statement queries.
Asynchronous Queries ¶
The Go Snowflake Driver supports asynchronous execution of SQL statements. Asynchronous execution allows you to start executing a statement and then retrieve the result later without being blocked while waiting. While waiting for the result of a SQL statement, you can perform other tasks, including executing other SQL statements.
Most of the steps to execute an asynchronous query are the same as the steps to execute a synchronous query. However, there is an additional step, which is that you must call the WithAsyncMode() function to update your Context object to specify that asynchronous mode is enabled.
In the code below, the call to "WithAsyncMode()" is specific to asynchronous mode. The rest of the code is compatible with both asynchronous mode and synchronous mode.
... // Update your Context object to specify asynchronous mode: ctx := WithAsyncMode(context.Background()) // Execute your query as usual by calling: rows, _ := db.QueryContext(ctx, query_string) // Retrieve the results as usual by calling: for rows.Next() { err := rows.Scan(...) ... }
The function db.QueryContext() returns an object of type snowflakeRows regardless of whether the query is synchronous or asynchronous. However:
- If the query is synchronous, then db.QueryContext() does not return until the query has finished and the result set has been loaded into the snowflakeRows object.
- If the query is asynchronous, then db.QueryContext() returns a potentially incomplete snowflakeRows object that is filled in later in the background.
The call to the Next() function of snowflakeRows is always synchronous (i.e. blocking). If the query has not yet completed and the snowflakeRows object (named "rows" in this example) has not been filled in yet, then rows.Next() waits until the result set has been filled in.
More generally, calls to any Golang SQL API function implemented in snowflakeRows or snowflakeResult are blocking calls, and wait if results are not yet available. (Examples of other synchronous calls include: snowflakeRows.Err(), snowflakeRows.Columns(), snowflakeRows.columnTypes(), snowflakeRows.Scan(), and snowflakeResult.RowsAffected().)
Because the example code above executes only one query and no other activity, there is no significant difference in behavior between asynchronous and synchronous behavior. The differences become significant if, for example, you want to perform some other activity after the query starts and before it completes. The example code below starts a query, which run in the background, and then retrieves the results later.
This example uses small SELECT statements that do not retrieve enough data to require asynchronous handling. However, the technique works for larger data sets, and for situations where the programmer might want to do other work after starting the queries and before retrieving the results. For a more elaborative example please see cmd/async/async.go
package gosnowflake import ( "context" "database/sql" "database/sql/driver" "fmt" "log" "os" sf "github.com/snowflakedb/gosnowflake" ) ... func DemonstrateAsyncMode(db *sql.DB) { // Enable asynchronous mode ctx := sf.WithAsyncMode(context.Background()) // Run the query with asynchronous context rows, err := db.QueryContext(ctx, "select 1") if err != nil { // handle error } // do something as the workflow continues whereas the query is computing in the background ... // Get the data when you are ready to handle it var val int err = rows.Scan(&val) if err != nil { // handle error } ... }
Support For PUT and GET ¶
The Go Snowflake Driver supports the PUT and GET commands.
The PUT command copies a file from a local computer (the computer where the Golang client is running) to a stage on the cloud platform. The GET command copies data files from a stage on the cloud platform to a local computer.
See the following for information on the syntax and supported parameters:
- PUT: https://docs.snowflake.com/en/sql-reference/sql/put.html
- GET: https://docs.snowflake.com/en/sql-reference/sql/get.html
## Using PUT
The following example shows how to run a PUT command by passing a string to the db.Query() function:
db.Query("PUT file://<local_file> <stage_identifier> <optional_parameters>")
"<local_file>" should include the file path as well as the name. Snowflake recommends using an absolute path rather than a relative path. For example:
db.Query("PUT file:///tmp/my_data_file @~ auto_compress=false overwrite=false")
Different client platforms (e.g. linux, Windows) have different path name conventions. Ensure that you specify path names appropriately. This is particularly important on Windows, which uses the backslash character as both an escape character and as a separator in path names.
To send information from a stream (rather than a file) use code similar to the code below. (The ReplaceAll() function is needed on Windows to handle backslashes in the path to the file.)
fileStream, _ := os.Open(fname) defer func() { if fileStream != nil { fileStream.Close() } } () sql := "put 'file://%v' @%%%v auto_compress=true parallel=30" sqlText := fmt.Sprintf(sql, strings.ReplaceAll(fname, "\\", "\\\\"), tableName) dbt.mustExecContext(WithFileStream(context.Background(), fileStream), sqlText)
Note: PUT statements are not supported for multi-statement queries.
## Using GET
The following example shows how to run a GET command by passing a string to the db.Query() function:
db.Query("GET <internal_stage_identifier> file://<local_file> <optional_parameters>")
"<local_file>" should include the file path as well as the name. Snowflake recommends using an absolute path rather than a relative path. For example:
db.Query("GET @~ file:///tmp/my_data_file auto_compress=false overwrite=false")
## Specifying temporary directory for encryption and compression
Putting and getting requires compression and/or encryption, which is done in the OS temporary directory. If you cannot use default temporary directory for your OS or you want to specify it yourself, you can use "tmpDirPath" DSN parameter. Remember, to encode slashes. Example:
u:p@a.r.c.snowflakecomputing.com/db/s?account=a.r.c&tmpDirPath=%2Fother%2Ftmp
## Using custom configuration for PUT/GET
If you want to override some default configuration options, you can use `WithFileTransferOptions` context. There are multiple config parameters including progress bars or compression.
Index ¶
- Constants
- Variables
- func Array(a interface{}, typ ...timezoneType) interface{}
- func DSN(cfg *Config) (dsn string, err error)
- func GetFromEnv(name string, failOnMissing bool) (string, error)
- func Location(offset int) *time.Location
- func LocationWithOffsetString(offsets string) (loc *time.Location, err error)
- func SFCallerPrettyfier(frame *runtime.Frame) (string, string)
- func SetLogger(inLogger *SFLogger)
- func WithArrowAllocator(ctx context.Context, pool memory.Allocator) context.Context
- func WithArrowBatches(ctx context.Context) context.Context
- func WithArrowBatchesTimestampOption(ctx context.Context, option snowflakeArrowBatchesTimestampOption) context.Context
- func WithArrowBatchesUtf8Validation(ctx context.Context) context.Context
- func WithAsyncMode(ctx context.Context) context.Context
- func WithDescribeOnly(ctx context.Context) context.Context
- func WithFetchResultByID(ctx context.Context, queryID string) context.Context
- func WithFileStream(ctx context.Context, reader io.Reader) context.Context
- func WithFileTransferOptions(ctx context.Context, options *SnowflakeFileTransferOptions) context.Context
- func WithHigherPrecision(ctx context.Context) context.Context
- func WithMultiStatement(ctx context.Context, num int) (context.Context, error)
- func WithOriginalTimestamp(ctx context.Context) context.Contextdeprecated
- func WithQueryIDChan(ctx context.Context, c chan<- string) context.Context
- func WithQueryTag(ctx context.Context, tag string) context.Context
- func WithRequestID(ctx context.Context, requestID UUID) context.Context
- func WithStreamDownloader(ctx context.Context) context.Context
- type ArrowBatch
- type ArrowStreamBatch
- type ArrowStreamLoader
- type AuthType
- type ClientConfig
- type ClientConfigCommonProps
- type Config
- type ConfigBool
- type ConfigParam
- type Connector
- type InternalClient
- type InternalSnowflakeDriver
- type OCSPFailOpenMode
- type SFLogger
- type SnowflakeConnection
- type SnowflakeDriver
- type SnowflakeError
- type SnowflakeFileTransferOptions
- type SnowflakeParameter
- type SnowflakeQueryStatus
- type SnowflakeResult
- type SnowflakeRows
- type SnowflakeStmt
- type TokenAccessor
- type TypedNullTime
- type UUID
Constants ¶
const ( // TimestampNTZType denotes a NTZ timezoneType for array binds TimestampNTZType timezoneType = iota // TimestampLTZType denotes a LTZ timezoneType for array binds TimestampLTZType // TimestampTZType denotes a TZ timezoneType for array binds TimestampTZType // DateType denotes a date type for array binds DateType // TimeType denotes a time type for array binds TimeType )
const ( // UseNanosecondTimestamp uses arrow.Timestamp in nanosecond precision, could cause ErrTooHighTimestampPrecision if arrow.Timestamp cannot fit original timestamp values. UseNanosecondTimestamp snowflakeArrowBatchesTimestampOption = iota // UseMicrosecondTimestamp uses arrow.Timestamp in microsecond precision UseMicrosecondTimestamp // UseMillisecondTimestamp uses arrow.Timestamp in millisecond precision UseMillisecondTimestamp // UseSecondTimestamp uses arrow.Timestamp in second precision UseSecondTimestamp // UseOriginalTimestamp uses original timestamp struct returned by Snowflake. It can be used in case arrow.Timestamp cannot fit original timestamp values. UseOriginalTimestamp )
const ( // ErrCodeEmptyAccountCode is an error code for the case where a DNS doesn't include account parameter ErrCodeEmptyAccountCode = 260000 // ErrCodeEmptyUsernameCode is an error code for the case where a DNS doesn't include user parameter ErrCodeEmptyUsernameCode = 260001 // ErrCodeEmptyPasswordCode is an error code for the case where a DNS doesn't include password parameter ErrCodeEmptyPasswordCode = 260002 // ErrCodeFailedToParseHost is an error code for the case where a DNS includes an invalid host name ErrCodeFailedToParseHost = 260003 // ErrCodeFailedToParsePort is an error code for the case where a DNS includes an invalid port number ErrCodeFailedToParsePort = 260004 // ErrCodeIdpConnectionError is an error code for the case where a IDP connection failed ErrCodeIdpConnectionError = 260005 // ErrCodeSSOURLNotMatch is an error code for the case where a SSO URL doesn't match ErrCodeSSOURLNotMatch = 260006 ErrCodeServiceUnavailable = 260007 // ErrCodeFailedToConnect is an error code for the case where a DB connection failed due to wrong account name ErrCodeFailedToConnect = 260008 // ErrCodeRegionOverlap is an error code for the case where a region is specified despite an account region present ErrCodeRegionOverlap = 260009 // ErrCodePrivateKeyParseError is an error code for the case where the private key is not parsed correctly ErrCodePrivateKeyParseError = 260010 // ErrCodeFailedToParseAuthenticator is an error code for the case where a DNS includes an invalid authenticator ErrCodeFailedToParseAuthenticator = 260011 // ErrCodeClientConfigFailed is an error code for the case where clientConfigFile is invalid or applying client configuration fails ErrCodeClientConfigFailed = 260012 // ErrFailedToPostQuery is an error code for the case where HTTP POST failed. ErrFailedToPostQuery = 261000 // ErrFailedToRenewSession is an error code for the case where session renewal failed. ErrFailedToRenewSession = 261001 // ErrFailedToCancelQuery is an error code for the case where cancel query failed. ErrFailedToCancelQuery = 261002 // ErrFailedToCloseSession is an error code for the case where close session failed. ErrFailedToCloseSession = 261003 // ErrFailedToAuth is an error code for the case where authentication failed for unknown reason. ErrFailedToAuth = 261004 // ErrFailedToAuthSAML is an error code for the case where authentication via SAML failed for unknown reason. ErrFailedToAuthSAML = 261005 // ErrFailedToAuthOKTA is an error code for the case where authentication via OKTA failed for unknown reason. ErrFailedToAuthOKTA = 261006 // ErrFailedToGetSSO is an error code for the case where authentication via OKTA failed for unknown reason. ErrFailedToGetSSO = 261007 // ErrFailedToParseResponse is an error code for when we cannot parse an external browser response from Snowflake. ErrFailedToParseResponse = 261008 // ErrFailedToGetExternalBrowserResponse is an error code for when there's an error reading from the open socket. ErrFailedToGetExternalBrowserResponse = 261009 // ErrFailedToHeartbeat is an error code when a heartbeat fails. ErrFailedToHeartbeat = 261010 // ErrFailedToGetChunk is an error code for the case where it failed to get chunk of result set ErrFailedToGetChunk = 262000 // ErrNoReadOnlyTransaction is an error code for the case where readonly mode is specified. ErrNoReadOnlyTransaction = 263000 // ErrNoDefaultTransactionIsolationLevel is an error code for the case where non default isolation level is specified. ErrNoDefaultTransactionIsolationLevel = 263001 // ErrInvalidStageFs is an error code denoting an invalid stage in the file system ErrInvalidStageFs = 264001 // ErrFailedToDownloadFromStage is an error code denoting the failure to download a file from the stage ErrFailedToDownloadFromStage = 264002 // ErrFailedToUploadToStage is an error code denoting the failure to upload a file to the stage ErrFailedToUploadToStage = 264003 // ErrInvalidStageLocation is an error code denoting an invalid stage location ErrInvalidStageLocation = 264004 // ErrLocalPathNotDirectory is an error code denoting a local path that is not a directory ErrLocalPathNotDirectory = 264005 // ErrFileNotExists is an error code denoting the file to be transferred does not exist ErrFileNotExists = 264006 // ErrCompressionNotSupported is an error code denoting the user specified compression type is not supported ErrCompressionNotSupported = 264007 // ErrInternalNotMatchEncryptMaterial is an error code denoting the encryption material specified does not match ErrInternalNotMatchEncryptMaterial = 264008 // ErrCommandNotRecognized is an error code denoting the PUT/GET command was not recognized ErrCommandNotRecognized = 264009 // ErrFailedToConvertToS3Client is an error code denoting the failure of an interface to s3.Client conversion ErrFailedToConvertToS3Client = 264010 // ErrNotImplemented is an error code denoting the file transfer feature is not implemented ErrNotImplemented = 264011 // ErrInvalidPadding is an error code denoting the invalid padding of decryption key ErrInvalidPadding = 264012 // ErrBindSerialization is an error code for a failed serialization of bind variables ErrBindSerialization = 265001 // ErrBindUpload is an error code for the uploading process of bind elements to the stage ErrBindUpload = 265002 // ErrAsync is an error code for an unknown async error ErrAsync = 266001 // ErrNoResultIDs is an error code for empty result IDs for multi statement queries ErrNoResultIDs = 267001 // ErrInvalidTimestampTz is an error code for the case where a returned TIMESTAMP_TZ internal value is invalid ErrInvalidTimestampTz = 268000 // ErrInvalidOffsetStr is an error code for the case where a offset string is invalid. The input string must // consist of sHHMI where one sign character '+'/'-' followed by zero filled hours and minutes ErrInvalidOffsetStr = 268001 // ErrInvalidBinaryHexForm is an error code for the case where a binary data in hex form is invalid. ErrInvalidBinaryHexForm = 268002 // ErrTooHighTimestampPrecision is an error code for the case where cannot convert Snowflake timestamp to arrow.Timestamp ErrTooHighTimestampPrecision = 268003 // ErrOCSPStatusRevoked is an error code for the case where the certificate is revoked. ErrOCSPStatusRevoked = 269001 // ErrOCSPStatusUnknown is an error code for the case where the certificate revocation status is unknown. ErrOCSPStatusUnknown = 269002 // ErrOCSPInvalidValidity is an error code for the case where the OCSP response validity is invalid. ErrOCSPInvalidValidity = 269003 // ErrOCSPNoOCSPResponderURL is an error code for the case where the OCSP responder URL is not attached. ErrOCSPNoOCSPResponderURL = 269004 // ErrQueryStatus when check the status of a query, receive error or no status ErrQueryStatus = 279001 // ErrQueryIDFormat the query ID given to fetch its result is not valid ErrQueryIDFormat = 279101 // ErrQueryReportedError server side reports the query failed with error ErrQueryReportedError = 279201 // ErrQueryIsRunning the query is still running ErrQueryIsRunning = 279301 // ErrSessionGone is an GS error code for the case that session is already closed ErrSessionGone = 390111 // ErrRoleNotExist is a GS error code for the case that the role specified does not exist ErrRoleNotExist = 390189 // ErrObjectNotExistOrAuthorized is a GS error code for the case that the server-side object specified does not exist ErrObjectNotExistOrAuthorized = 390201 )
const ( SFQueryRunning queryResultStatus = iota SFQueryAborting SFQuerySuccess SFQueryFailedWithError SFQueryAborted SFQueryQueued SFQueryFailedWithIncident SFQueryDisconnected SFQueryResumingWarehouse // SFQueryQueueRepairingWarehouse present in QueryDTO.java. SFQueryQueueRepairingWarehouse SFQueryRestarted // SFQueryBlocked is when a statement is waiting on a lock on resource held // by another statement. SFQueryBlocked SFQueryNoData )
Query Status defined at server side
const ( // QueryStatusInProgress denotes a query execution in progress QueryStatusInProgress queryStatus = "queryStatusInProgress" // QueryStatusComplete denotes a completed query execution QueryStatusComplete queryStatus = "queryStatusComplete" // QueryFailed denotes a failed query QueryFailed queryStatus = "queryFailed" )
const ( // SQLStateNumericValueOutOfRange is a SQL State code indicating Numeric value is out of range. SQLStateNumericValueOutOfRange = "22003" // SQLStateInvalidDataTimeFormat is a SQL State code indicating DataTime format is invalid. SQLStateInvalidDataTimeFormat = "22007" // SQLStateConnectionWasNotEstablished is a SQL State code indicating connection was not established. SQLStateConnectionWasNotEstablished = "08001" // SQLStateConnectionRejected is a SQL State code indicating connection was rejected. SQLStateConnectionRejected = "08004" // SQLStateConnectionFailure is a SQL State code indicating connection failed. SQLStateConnectionFailure = "08006" // SQLStateFeatureNotSupported is a SQL State code indicating the feature is not enabled. SQLStateFeatureNotSupported = "0A000" )
const SFSessionIDKey contextKey = "LOG_SESSION_ID"
SFSessionIDKey is context key of session id
const SFSessionUserKey contextKey = "LOG_USER"
SFSessionUserKey is context key of user id of a session
const SnowflakeGoDriverVersion = "1.9.0"
SnowflakeGoDriverVersion is the version of Go Snowflake Driver.
Variables ¶
var ( // DataTypeFixed is a FIXED datatype. DataTypeFixed = []byte{fixedType.Byte()} // DataTypeReal is a REAL datatype. DataTypeReal = []byte{realType.Byte()} // DataTypeText is a TEXT datatype. DataTypeText = []byte{textType.Byte()} // DataTypeDate is a Date datatype. DataTypeDate = []byte{dateType.Byte()} // DataTypeVariant is a TEXT datatype. DataTypeVariant = []byte{variantType.Byte()} // DataTypeTimestampLtz is a TIMESTAMP_LTZ datatype. DataTypeTimestampLtz = []byte{timestampLtzType.Byte()} // DataTypeTimestampNtz is a TIMESTAMP_NTZ datatype. DataTypeTimestampNtz = []byte{timestampNtzType.Byte()} // DataTypeTimestampTz is a TIMESTAMP_TZ datatype. DataTypeTimestampTz = []byte{timestampTzType.Byte()} // DataTypeObject is a OBJECT datatype. DataTypeObject = []byte{objectType.Byte()} // DataTypeArray is a ARRAY datatype. DataTypeArray = []byte{arrayType.Byte()} // DataTypeBinary is a BINARY datatype. DataTypeBinary = []byte{binaryType.Byte()} // DataTypeTime is a TIME datatype. DataTypeTime = []byte{timeType.Byte()} // DataTypeBoolean is a BOOLEAN datatype. DataTypeBoolean = []byte{booleanType.Byte()} )
var ( // MaxChunkDownloadWorkers specifies the maximum number of goroutines used to download chunks MaxChunkDownloadWorkers = 10 // CustomJSONDecoderEnabled has the chunk downloader use the custom JSON decoder to reduce memory footprint. CustomJSONDecoderEnabled = false )
var LogKeys = [...]contextKey{SFSessionIDKey, SFSessionUserKey}
LogKeys these keys in context should be included in logging messages when using logger.WithContext
var SnowflakeTransport = &http.Transport{ TLSClientConfig: &tls.Config{ RootCAs: certPool, VerifyPeerCertificate: verifyPeerCertificateSerial, }, MaxIdleConns: 10, IdleConnTimeout: 30 * time.Minute, Proxy: http.ProxyFromEnvironment, DialContext: (&net.Dialer{ Timeout: 30 * time.Second, KeepAlive: 30 * time.Second, }).DialContext, }
SnowflakeTransport includes the certificate revocation check with OCSP in sequential. By default, the driver uses this transport object.
var SnowflakeTransportTest = SnowflakeTransport
SnowflakeTransportTest includes the certificate revocation check in parallel
Functions ¶
func Array ¶
func Array(a interface{}, typ ...timezoneType) interface{}
Array takes in a column of a row to be inserted via array binding, bulk or otherwise, and converts it into a native snowflake type for binding
func GetFromEnv ¶ added in v1.9.0
GetFromEnv is used to get the value of an environment variable from the system
func LocationWithOffsetString ¶
LocationWithOffsetString returns an offset based Location object. The offset string must consist of sHHMI where one sign character '+'/'-' followed by zero filled hours and minutes.
func SFCallerPrettyfier ¶
SFCallerPrettyfier to provide base file name and function name from calling frame used in SFLogger
func SetLogger ¶
func SetLogger(inLogger *SFLogger)
SetLogger set a new logger of SFLogger interface for gosnowflake
func WithArrowAllocator ¶ added in v1.9.0
WithArrowAllocator returns a context embedding the provided allocator which will be utilized by chunk downloaders when constructing Arrow objects.
func WithArrowBatches ¶
WithArrowBatches returns a context that allows users to retrieve arrow.Record download workers upon querying
func WithArrowBatchesTimestampOption ¶ added in v1.9.0
func WithArrowBatchesTimestampOption(ctx context.Context, option snowflakeArrowBatchesTimestampOption) context.Context
WithArrowBatchesTimestampOption in combination with WithArrowBatches returns a context that allows users to retrieve arrow.Record with different timestamp options. UseNanosecondTimestamp: arrow.Timestamp in nanosecond precision, could cause ErrTooHighTimestampPrecision if arrow.Timestamp cannot fit original timestamp values. UseMicrosecondTimestamp: arrow.Timestamp in microsecond precision UseMillisecondTimestamp: arrow.Timestamp in millisecond precision UseSecondTimestamp: arrow.Timestamp in second precision UseOriginalTimestamp: original timestamp struct returned by Snowflake. It can be used in case arrow.Timestamp cannot fit original timestamp values.
func WithArrowBatchesUtf8Validation ¶ added in v1.9.0
WithArrowBatchesUtf8Validation in combination with WithArrowBatches returns a context that will validate and replace invalid UTF-8 characters in string columns with the replacement character Theoretically, this should not be necessary, because arrow string column is only intended to contain valid UTF-8 characters. However, in practice, it is possible that the data in the string column is not valid UTF-8.
func WithAsyncMode ¶
WithAsyncMode returns a context that allows execution of query in async mode
func WithDescribeOnly ¶
WithDescribeOnly returns a context that enables a describe only query
func WithFetchResultByID ¶
WithFetchResultByID returns a context that allows retrieving the result by query ID
func WithFileStream ¶
WithFileStream returns a context that contains the address of the file stream to be PUT
func WithFileTransferOptions ¶
func WithFileTransferOptions(ctx context.Context, options *SnowflakeFileTransferOptions) context.Context
WithFileTransferOptions returns a context that contains the address of file transfer options
func WithHigherPrecision ¶
WithHigherPrecision returns a context that enables higher precision by returning a *big.Int or *big.Float variable when querying rows for column types with numbers that don't fit into its native Golang counterpart When used in combination with WithArrowBatches, original BigDecimal in arrow batches will be preserved.
func WithMultiStatement ¶
WithMultiStatement returns a context that allows the user to execute the desired number of sql queries in one query
func WithOriginalTimestamp
deprecated
added in
v1.9.0
WithOriginalTimestamp in combination with WithArrowBatches returns a context that allows users to retrieve arrow.Record with original timestamp struct returned by Snowflake. It can be used in case arrow.Timestamp cannot fit original timestamp values.
Deprecated: please use WithArrowBatchesTimestampOption instead.
func WithQueryIDChan ¶
WithQueryIDChan returns a context that contains the channel to receive the query ID
func WithQueryTag ¶ added in v1.9.0
WithQueryTag returns a context that will set the given tag as the QUERY_TAG parameter on any queries that are run
func WithRequestID ¶
WithRequestID returns a new context with the specified snowflake request id
Types ¶
type ArrowBatch ¶
type ArrowBatch struct {
// contains filtered or unexported fields
}
ArrowBatch object represents a chunk of data, or subset of rows, retrievable in arrow.Record format
func (*ArrowBatch) ArrowSnowflakeTimestampToTime ¶ added in v1.9.0
func (rb *ArrowBatch) ArrowSnowflakeTimestampToTime(rec arrow.Record, colIdx int, recIdx int) *time.Time
ArrowSnowflakeTimestampToTime converts original timestamp returned by Snowflake to time.Time
func (*ArrowBatch) Fetch ¶
func (rb *ArrowBatch) Fetch() (*[]arrow.Record, error)
Fetch returns an array of records representing a chunk in the query
func (*ArrowBatch) GetRowCount ¶ added in v1.9.0
func (rb *ArrowBatch) GetRowCount() int
GetRowCount returns the number of rows in an arrow batch
func (*ArrowBatch) WithContext ¶ added in v1.9.0
func (rb *ArrowBatch) WithContext(ctx context.Context) *ArrowBatch
WithContext sets the context which will be used for this ArrowBatch.
type ArrowStreamBatch ¶ added in v1.9.0
ArrowStreamBatch is a type describing a potentially yet-to-be-downloaded Arrow IPC stream. Call `GetStream` to download and retrieve an io.Reader that can be used with ipc.NewReader to get record batch results.
func (*ArrowStreamBatch) GetStream ¶ added in v1.9.0
func (asb *ArrowStreamBatch) GetStream(ctx context.Context) (io.ReadCloser, error)
GetStream returns a stream of bytes consisting of an Arrow IPC Record batch stream. Close should be called on the returned stream when done to ensure no leaked memory.
func (*ArrowStreamBatch) NumRows ¶ added in v1.9.0
func (asb *ArrowStreamBatch) NumRows() int64
NumRows returns the total number of rows that the metadata stated should be in this stream of record batches.
type ArrowStreamLoader ¶ added in v1.9.0
type ArrowStreamLoader interface { GetBatches() ([]ArrowStreamBatch, error) TotalRows() int64 RowTypes() []execResponseRowType Location() *time.Location JSONData() [][]*string }
ArrowStreamLoader is a convenience interface for downloading Snowflake results via multiple Arrow Record Batch streams.
Some queries from Snowflake do not return Arrow data regardless of the settings, such as "SHOW WAREHOUSES". In these cases, you'll find TotalRows() > 0 but GetBatches returns no batches and no errors. In this case, the data is accessible via JSONData with the actual types matching up to the metadata in RowTypes.
type AuthType ¶
type AuthType int
AuthType indicates the type of authentication in Snowflake
const ( // AuthTypeSnowflake is the general username password authentication AuthTypeSnowflake AuthType = iota // AuthTypeOAuth is the OAuth authentication AuthTypeOAuth // AuthTypeExternalBrowser is to use a browser to access an Fed and perform SSO authentication AuthTypeExternalBrowser // AuthTypeOkta is to use a native okta URL to perform SSO authentication on Okta AuthTypeOkta // AuthTypeJwt is to use Jwt to perform authentication AuthTypeJwt // AuthTypeTokenAccessor is to use the provided token accessor and bypass authentication AuthTypeTokenAccessor // AuthTypeUsernamePasswordMFA is to use username and password with mfa AuthTypeUsernamePasswordMFA )
type ClientConfig ¶ added in v1.9.0
type ClientConfig struct {
Common *ClientConfigCommonProps `json:"common"`
}
ClientConfig config root
type ClientConfigCommonProps ¶ added in v1.9.0
type ClientConfigCommonProps struct { LogLevel string `json:"log_level,omitempty"` LogPath string `json:"log_path,omitempty"` }
ClientConfigCommonProps properties from "common" section
type Config ¶
type Config struct { Account string // Account name User string // Username Password string // Password (requires User) Database string // Database name Schema string // Schema Warehouse string // Warehouse Role string // Role Region string // Region // ValidateDefaultParameters disable the validation checks for Database, Schema, Warehouse and Role // at the time a connection is established ValidateDefaultParameters ConfigBool Params map[string]*string // other connection parameters ClientIP net.IP // IP address for network check Protocol string // http or https (optional) Host string // hostname (optional) Port int // port (optional) Authenticator AuthType // The authenticator type Passcode string PasscodeInPassword bool OktaURL *url.URL LoginTimeout time.Duration // Login retry timeout EXCLUDING network roundtrip and read out http response RequestTimeout time.Duration // request retry timeout EXCLUDING network roundtrip and read out http response JWTExpireTimeout time.Duration // JWT expire after timeout ClientTimeout time.Duration // Timeout for network round trip + read out http response JWTClientTimeout time.Duration // Timeout for network round trip + read out http response used when JWT token auth is taking place ExternalBrowserTimeout time.Duration // Timeout for external browser login MaxRetryCount int // Specifies how many times non-periodic HTTP request can be retried Application string // application name. InsecureMode bool // driver doesn't check certificate revocation status OCSPFailOpen OCSPFailOpenMode // OCSP Fail Open Token string // Token to use for OAuth other forms of token based auth TokenAccessor TokenAccessor // Optional token accessor to use KeepSessionAlive bool // Enables the session to persist even after the connection is closed PrivateKey *rsa.PrivateKey // Private key used to sign JWT Transporter http.RoundTripper // RoundTripper to intercept HTTP requests and responses DisableTelemetry bool // indicates whether to disable telemetry Tracing string // sets logging level TmpDirPath string // sets temporary directory used by a driver for operations like encrypting, compressing etc MfaToken string // Internally used to cache the MFA token IDToken string // Internally used to cache the Id Token for external browser ClientRequestMfaToken ConfigBool // When true the MFA token is cached in the credential manager. True by default in Windows/OSX. False for Linux. ClientStoreTemporaryCredential ConfigBool // When true the ID token is cached in the credential manager. True by default in Windows/OSX. False for Linux. DisableQueryContextCache bool // Should HTAP query context cache be disabled IncludeRetryReason ConfigBool // Should retried request contain retry reason ClientConfigFile string // File path to the client configuration json file DisableConsoleLogin ConfigBool // Indicates whether console login should be disabled }
Config is a set of configuration parameters
func GetConfigFromEnv ¶ added in v1.9.0
func GetConfigFromEnv(properties []*ConfigParam) (*Config, error)
GetConfigFromEnv is used to parse the environment variable values to specific fields of the Config
type ConfigBool ¶
type ConfigBool uint8
ConfigBool is a type to represent true or false in the Config
const ( // ConfigBoolTrue represents true for the config field ConfigBoolTrue ConfigBool // ConfigBoolFalse represents false for the config field ConfigBoolFalse )
type ConfigParam ¶ added in v1.9.0
ConfigParam is used to bind the name of the Config field with the environment variable and set the requirement for it
type Connector ¶
type Connector struct {
// contains filtered or unexported fields
}
Connector creates Driver with the specified Config
func NewConnector ¶
func NewConnector(driver InternalSnowflakeDriver, config Config) Connector
NewConnector creates a new connector with the given SnowflakeDriver and Config.
type InternalClient ¶
type InternalClient interface { Get(context.Context, *url.URL, map[string]string, time.Duration) (*http.Response, error) Post(context.Context, *url.URL, map[string]string, []byte, time.Duration, currentTimeProvider) (*http.Response, error) }
InternalClient is implemented by HTTPClient
type InternalSnowflakeDriver ¶
type InternalSnowflakeDriver interface { Open(dsn string) (driver.Conn, error) OpenWithConfig(ctx context.Context, config Config) (driver.Conn, error) }
InternalSnowflakeDriver is the interface for an internal Snowflake driver
type OCSPFailOpenMode ¶
type OCSPFailOpenMode uint32
OCSPFailOpenMode is OCSP fail open mode. OCSPFailOpenTrue by default and may set to ocspModeFailClosed for fail closed mode
const ( // OCSPFailOpenTrue represents OCSP fail open mode. OCSPFailOpenTrue OCSPFailOpenMode // OCSPFailOpenFalse represents OCSP fail closed mode. OCSPFailOpenFalse )
type SFLogger ¶
type SFLogger interface { rlog.Ext1FieldLogger SetLogLevel(level string) error GetLogLevel() string WithContext(ctx context.Context) *rlog.Entry SetOutput(output io.Writer) CloseFileOnLoggerReplace(file *os.File) error Replace(newLogger *SFLogger) }
SFLogger Snowflake logger interface to expose FieldLogger defined in logrus
func CreateDefaultLogger ¶
func CreateDefaultLogger() SFLogger
CreateDefaultLogger return a new instance of SFLogger with default config
type SnowflakeConnection ¶
type SnowflakeConnection interface {
GetQueryStatus(ctx context.Context, queryID string) (*SnowflakeQueryStatus, error)
}
SnowflakeConnection is a wrapper to snowflakeConn that exposes API functions
type SnowflakeDriver ¶
type SnowflakeDriver struct{}
SnowflakeDriver is a context of Go Driver
func (SnowflakeDriver) Open ¶
func (d SnowflakeDriver) Open(dsn string) (driver.Conn, error)
Open creates a new connection.
func (SnowflakeDriver) OpenWithConfig ¶
OpenWithConfig creates a new connection with the given Config.
type SnowflakeError ¶
type SnowflakeError struct { Number int SQLState string QueryID string Message string MessageArgs []interface{} IncludeQueryID bool // TODO: populate this in connection }
SnowflakeError is a error type including various Snowflake specific information.
func (*SnowflakeError) Error ¶
func (se *SnowflakeError) Error() string
type SnowflakeFileTransferOptions ¶
type SnowflakeFileTransferOptions struct { RaisePutGetError bool MultiPartThreshold int64 // contains filtered or unexported fields }
SnowflakeFileTransferOptions enables users to specify options regarding files transfers such as PUT/GET
type SnowflakeParameter ¶
type SnowflakeParameter struct { Key string Value string Default string Level string Description string SetByUser string SetInJob string SetOn string SetByThreadID string SetByThreadName string SetByClass string ParameterComment string Type string IsExpired string ExpiresAt string SetByControllingParameter string ActivateVersion string PartialRollout string Unknown string // Reserve for added parameter }
SnowflakeParameter includes the columns output from SHOW PARAMETER command.
func ScanSnowflakeParameter ¶
func ScanSnowflakeParameter(rows *sql.Rows) (*SnowflakeParameter, error)
ScanSnowflakeParameter binds SnowflakeParameter variable with an array of column buffer.
type SnowflakeQueryStatus ¶
type SnowflakeQueryStatus struct { SQLText string StartTime int64 EndTime int64 ErrorCode string ErrorMessage string ScanBytes int64 ProducedRows int64 }
SnowflakeQueryStatus is the query status metadata of a snowflake query
type SnowflakeResult ¶
type SnowflakeResult interface { GetQueryID() string GetStatus() queryStatus GetArrowBatches() ([]*ArrowBatch, error) }
SnowflakeResult provides an API for methods exposed to the clients
type SnowflakeRows ¶ added in v1.9.0
type SnowflakeRows interface { GetQueryID() string GetStatus() queryStatus GetArrowBatches() ([]*ArrowBatch, error) }
SnowflakeRows provides an API for methods exposed to the clients
type SnowflakeStmt ¶ added in v1.9.0
type SnowflakeStmt interface {
GetQueryID() string
}
SnowflakeStmt represents the prepared statement in driver.
type TokenAccessor ¶
type TokenAccessor interface { GetTokens() (token string, masterToken string, sessionID int64) SetTokens(token string, masterToken string, sessionID int64) Lock() error Unlock() }
TokenAccessor manages the session token and master token
type TypedNullTime ¶ added in v1.9.0
TypedNullTime is required to properly bind the null value with the snowflakeType as the Snowflake functions require the type of the field to be provided explicitly for the null values
Source Files
¶
- arrow_chunk.go
- async.go
- auth.go
- authexternalbrowser.go
- authokta.go
- azure_storage_client.go
- bind_uploader.go
- cacert.go
- chunk.go
- chunk_downloader.go
- client.go
- client_configuration.go
- connection.go
- connection_util.go
- connector.go
- converter.go
- datatype.go
- datetime.go
- doc.go
- driver.go
- dsn.go
- easy_logging.go
- encrypt_util.go
- errors.go
- file_compression_type.go
- file_transfer_agent.go
- file_util.go
- gcs_storage_client.go
- heartbeat.go
- htap.go
- local_storage_client.go
- location.go
- log.go
- monitoring.go
- multistatement.go
- ocsp.go
- priv_key_test_coding_helper.go
- query.go
- release.go
- restful.go
- result.go
- retry.go
- rows.go
- s3_storage_client.go
- secret_detector.go
- secure_storage_manager.go
- sqlstate.go
- statement.go
- storage_client.go
- telemetry.go
- transaction.go
- url_util.go
- util.go
- uuid.go
- version.go
Directories
¶
Path | Synopsis |
---|---|
benchmark
|
|
jsonresultset
Package jsonresultset is a benchmark for large json result sets
|
Package jsonresultset is a benchmark for large json result sets |
largesetresult
Package largesetresult is a benchmark for large result sets
|
Package largesetresult is a benchmark for large result sets |
cmd
|
|
filestransfer
Example: Files transfer using PUT/GET commands
|
Example: Files transfer using PUT/GET commands |
keepalive
Example: client session keep alive By default, the token expires in 4 hours if the connection is idle.
|
Example: client session keep alive By default, the token expires in 4 hours if the connection is idle. |
noconnpool
Example: No connection pool
|
Example: No connection pool |
oauth
Example: Authenticate with OAuth.
|
Example: Authenticate with OAuth. |
select1
Example: Fetch one row.
|
Example: Fetch one row. |
selectmany
Example: Fetch many rows and allow cancel the query by Ctrl+C.
|
Example: Fetch many rows and allow cancel the query by Ctrl+C. |
showparam
Example: Set the session parameter in DSN and verify it
|
Example: Set the session parameter in DSN and verify it |
verifycert
Example: Verify SSL/TLS certificate with OCSP revocation check
|
Example: Verify SSL/TLS certificate with OCSP revocation check |