gosnowflake

README

********************************************************************************
Go Snowflake Driver
********************************************************************************

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This topic provides instructions for installing, running, and modifying the Go Snowflake Driver. The driver supports Go's `database/sql <https://golang.org/pkg/database/sql/>`_ package.

Prerequisites
================================================================================

The following software packages are required to use the Go Snowflake Driver.

Go
----------------------------------------------------------------------

The latest driver requires the `Go language <https://golang.org/>`_ 1.14 or higher. The supported operating systems are Linux, Mac OS, and Windows, but you may run the driver on other platforms if the Go language works correctly on those platforms.


Installation
================================================================================

Get Gosnowflake source code, if not installed.

.. code-block:: bash

    go get -u github.com/magna5/gosnowflake

Docs
====

For detailed documentation and basic usage examples, please see the documentation at
`godoc.org <https://godoc.org/github.com/magna5/gosnowflake/>`_.

Sample Programs
================================================================================

Snowflake provides a set of sample programs to test with. Set the environment variable ``$GOPATH`` to the top directory of your workspace, e.g., ``~/go`` and make certain to 
include ``$GOPATH/bin`` in the environment variable ``$PATH``. Run the ``make`` command to build all sample programs.

.. code-block:: go

    make install

In the following example, the program ``select1.go`` is built and installed in ``$GOPATH/bin`` and can be run from the command line:

.. code-block:: bash

    SNOWFLAKE_TEST_ACCOUNT=<your_account> \
    SNOWFLAKE_TEST_USER=<your_user> \
    SNOWFLAKE_TEST_PASSWORD=<your_password> \
    select1
    Congrats! You have successfully run SELECT 1 with Snowflake DB!

Development
================================================================================

The developer notes are hosted with the source code on `GitHub <https://github.com/magna5/gosnowflake>`_.

Testing Code
----------------------------------------------------------------------

Set the Snowflake connection info in ``parameters.json``:

.. code-block:: json

    {
        "testconnection": {
            "SNOWFLAKE_TEST_USER":      "<your_user>",
            "SNOWFLAKE_TEST_PASSWORD":  "<your_password>",
            "SNOWFLAKE_TEST_ACCOUNT":   "<your_account>",
            "SNOWFLAKE_TEST_WAREHOUSE": "<your_warehouse>",
            "SNOWFLAKE_TEST_DATABASE":  "<your_database>",
            "SNOWFLAKE_TEST_SCHEMA":    "<your_schema>",
            "SNOWFLAKE_TEST_ROLE":      "<your_role>"
        }
    }

Install `jq <https://stedolan.github.io/jq/>`_ so that the parameters can get parsed correctly, and run ``make test`` in your Go development environment:

.. code-block:: bash

    make test

Submitting Pull Requests
----------------------------------------------------------------------

You may use your preferred editor to edit the driver code. Make certain to run ``make fmt lint`` before submitting any pull request to Snowflake. This command formats your source code according to the standard Go style and detects any coding style issues.

Support
----------------------------------------------------------------------

For official support, contact Snowflake support at:
https://support.snowflake.net/

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/magna5/gosnowflake"
)

func main() {
	db, err := sql.Open("snowflake", "user:password@myaccount/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]@accountname/dbname/schemaname[?param1=value&...&paramN=valueN
• username[:password]@accountname/dbname[?param1=value&...&paramN=valueN
• username[:password]@hostname:port/dbname/schemaname?account=<your_account>[&param1=value&...&paramN=valueN]

where all parameters must be escaped or use `Config` and `DSN` to construct a DSN string.

The following example opens a database handle with the Snowflake account myaccount 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@myaccount/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 the name of your Snowflake account, where string is the name assigned to your account by Snowflake. In the URL you received from Snowflake, your account name is the first segment in the domain (e.g. abc123 in https://abc123.snowflakecomputing.com). This parameter is optional if your account is specified after the @ character. If you are not on us-west-2 region or AWS deployment, then append the region after the account name, e.g. “<account>.<region>”. If you are not on AWS deployment, then append not only the region, but also the platform, e.g., “<account>.<region>.<platform>”. Account, region, and platform should be separated by a period (“.”), as shown above. If you are using a global url, then append connection group and "global", e.g., "account-<connection_group>.global". Account and connection group are separated by a dash ("-"), as shown above.

• 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.

• 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

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. :code:`no_proxy=.amazonaws.com` means that AWS 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 request ID

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:

ctxWithID := WithRequestID(ctx, "app-request-id-...")
rows, err := db.QueryContext(ctxWithID, query)

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

Queries return SQL column type information in the ColumnType type. The DatabaseTypeName method returns strings representing Snowflake data types. The following table shows those strings, the corresponding Snowflake data type, and the corresponding Golang native data type. The columns are:

1. The string representation of the data type.
2. The SQL data type.
3. 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 JSON strings.)
4. The standard Golang data type that is returned when you use SnowflakeRows.Scan() to read data from JSON data format directly.
5. Footnotes numbers.

This table shows the data types:

=============================================================================================
               |                                    | Default Go  | Supported  |
String         |                                    | Data Type   | Go Data    |
Representation | Snowflake Data Type                | for Scan()  | Types for  | Footnotes
               |                                    | interface{} | Scan()     |
               |                                    | (JSON)      | (JSON)     |
==============================================================================================
BOOLEAN        | BOOLEAN                            | string      | bool       |
TEXT           | VARCHAR/STRING                     | string      | string     |
REAL           | REAL/DOUBLE                        | string      | float64    | [1]  [2]
FIXED          | INTEGER that fits in int64         | string      | int64      | [1]  [2]
FIXED          | NUMBER(P, S) where S > 0           | string      |            | [1]  [3]
DATE           | DATE                               | string      | time.Time  |
TIME           | TIME                               | string      | time.Time  |
TIMESTAMP_LTZ  | TIMESTAMP_LTZ                      | string      | time.Time  |
TIMESTAMP_NTZ  | TIMESTAMP_NTZ                      | string      | time.Time  |
TIMESTAMP_TZ   | TIMESTAMP_TZ                       | string      | time.Time  |
BINARY         | BINARY                             | string      | []byte     |
ARRAY          | ARRAY                              | string      | string     |
OBJECT         | OBJECT                             | string      | string     |
VARIANT        | VARIANT                            | string      | string     |

Footnotes:

[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] If the value in Snowflake is too large to fit into the corresponding Golang data type, then conversion can return either an int64 with the high bits truncated or an error.

Note: SQL NULL values are converted to Golang nil values, and vice-versa.

Binding Parameters to Array Variables For Batch Inserts

Version 1.3.9 (and later) of the Go Snowflake Driver supports the ability to bind an array variable to a parameter in an 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 into the table.
_, err = db.Exec("insert into my_table values (?, ?, ?, ?)", intArray, fltArray, boolArray, strArray)

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).

Binding a Parameter to a Time Type

Go's database/sql package supports the ability to bind a parameter in an 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/magna5/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 doesn't 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 doesn't help reduce memory footprint by itself. Consider Custom JSON Decoder.

import (
	sf "github.com/magna5/gosnowflake"
)
sf.MaxChunkDownloadWorkers = 2

Experimental: Custom JSON Decoder for parsing Result Set

The application may have the driver use a custom JSON decoder that incrementally parses the result set as follows.

import (
	sf "github.com/magna5/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: "SNOWFLAKE_JWT"
	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.

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 results of the individual statements. 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 results 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.

If any of the SQL statements fail to compile or execute, execution is aborted. Any previous statements that ran before 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.

Limitations

GET and PUT operations are unsupported.

Index

• Constants
• Variables
• func DSN(cfg *Config) (dsn string, err 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 WithAsyncMode(ctx context.Context) (context.Context, error)
• func WithMultiStatement(ctx context.Context, num int) (context.Context, error)
• func WithQueryIDChan(ctx context.Context, c chan<- string) context.Context
• func WithRequestID(ctx context.Context, requestID string) context.Context
• type AuthType
  • func (authType AuthType) String() string
• type Config
  • func ParseDSN(dsn string) (cfg *Config, err error)
• type ConfigBool
• type Connector
  • func NewConnector(driver InternalSnowflakeDriver, config Config) Connector
  • func (t Connector) Connect(ctx context.Context) (driver.Conn, error)
  • func (t Connector) Driver() driver.Driver
• type InternalSnowflakeDriver
• type OCSPFailOpenMode
• type SFLogger
  • func CreateDefaultLogger() SFLogger
  • func GetLogger() SFLogger
• type SnowflakeDriver
  • func (d SnowflakeDriver) Open(dsn string) (driver.Conn, error)
  • func (d SnowflakeDriver) OpenWithConfig(ctx context.Context, config Config) (driver.Conn, error)
• type SnowflakeError
  • func (se *SnowflakeError) Error() string
• type SnowflakeParameter
  • func ScanSnowflakeParameter(rows *sql.Rows) (*SnowflakeParameter, error)
• type SnowflakeResult
• type SnowflakeRows
  • func (rows *SnowflakeRows) Close() (err error)
  • func (rows *SnowflakeRows) ColumnTypeDatabaseTypeName(index int) string
  • func (rows *SnowflakeRows) ColumnTypeLength(index int) (length int64, ok bool)
  • func (rows *SnowflakeRows) ColumnTypeNullable(index int) (nullable, ok bool)
  • func (rows *SnowflakeRows) ColumnTypePrecisionScale(index int) (precision, scale int64, ok bool)
  • func (rows *SnowflakeRows) ColumnTypeScanType(index int) reflect.Type
  • func (rows *SnowflakeRows) Columns() []string
  • func (rows *SnowflakeRows) GetQueryID() string
  • func (rows *SnowflakeRows) GetStatus() queryStatus
  • func (rows *SnowflakeRows) HasNextResultSet() bool
  • func (rows *SnowflakeRows) Next(dest []driver.Value) (err error)
  • func (rows *SnowflakeRows) NextResultSet() error

Constants

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 is an error code for the case where service is unavailable.
	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

	// 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

	// 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

	// 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

	// 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 (

	// QueryStatusWaiting denotes a query execution waiting to happen
	QueryStatusWaiting queryStatus = "queryStatusWaiting"
	// 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 (
	// MultiStatementCount controls the number of queries to execute in a single API call
	MultiStatementCount paramKey = "MULTI_STATEMENT_COUNT"
	// AsyncMode tells the server to not block the request on executing the entire query
	AsyncMode paramKey = "ASYNC_MODE_QUERY"
	// QueryIDChan is the channel to receive the query ID from
	QueryIDChan paramKey = "QUERY_ID_CHANNEL"
)

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 = "1.3.13"

SnowflakeGoDriverVersion is the version of Go Snowflake Driver.

const SnowflakeRequestIDKey contextKey = "SNOWFLAKE_REQUEST_ID"

SnowflakeRequestIDKey is optional context key to specify request id

Variables

var (
	// DataTypeFixed is a FIXED datatype.
	DataTypeFixed = []byte{fixedType}
	// DataTypeReal is a REAL datatype.
	DataTypeReal = []byte{realType}
	// DataTypeText is a TEXT datatype.
	DataTypeText = []byte{textType}
	// DataTypeDate is a Date datatype.
	DataTypeDate = []byte{dateType}
	// DataTypeVariant is a TEXT datatype.
	DataTypeVariant = []byte{variantType}
	// DataTypeTimestampLtz is a TIMESTAMP_LTZ datatype.
	DataTypeTimestampLtz = []byte{timestampLtzType}
	// DataTypeTimestampNtz is a TIMESTAMP_NTZ datatype.
	DataTypeTimestampNtz = []byte{timestampNtzType}
	// DataTypeTimestampTz is a TIMESTAMP_TZ datatype.
	DataTypeTimestampTz = []byte{timestampTzType}
	// DataTypeObject is a OBJECT datatype.
	DataTypeObject = []byte{objectType}
	// DataTypeArray is a ARRAY datatype.
	DataTypeArray = []byte{arrayType}
	// DataTypeBinary is a BINARY datatype.
	DataTypeBinary = []byte{binaryType}
	// DataTypeTime is a TIME datatype.
	DataTypeTime = []byte{timeType}
	// DataTypeBoolean is a BOOLEAN datatype.
	DataTypeBoolean = []byte{booleanType}
)

var (
	// ErrEmptyAccount is returned if a DNS doesn't include account parameter.
	ErrEmptyAccount = &SnowflakeError{
		Number:  ErrCodeEmptyAccountCode,
		Message: "account is empty",
	}
	// ErrEmptyUsername is returned if a DNS doesn't include user parameter.
	ErrEmptyUsername = &SnowflakeError{
		Number:  ErrCodeEmptyUsernameCode,
		Message: "user is empty",
	}
	// ErrEmptyPassword is returned if a DNS doesn't include password parameter.
	ErrEmptyPassword = &SnowflakeError{
		Number:  ErrCodeEmptyPasswordCode,
		Message: "password is empty"}

	// ErrInvalidRegion is returned if a DSN's implicit region from account parameter and explicit region parameter conflict.
	ErrInvalidRegion = &SnowflakeError{
		Number:  ErrCodeRegionOverlap,
		Message: "two regions specified"}
)

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 DSN

func DSN(cfg *Config) (dsn string, err error)

DSN constructs a DSN for Snowflake db.

func Location

func Location(offset int) *time.Location

Location returns an offset (minutes) based Location object for Snowflake database.

func LocationWithOffsetString

func LocationWithOffsetString(offsets string) (loc *time.Location, err error)

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

func SFCallerPrettyfier(frame *runtime.Frame) (string, string)

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 WithAsyncMode

func WithAsyncMode(ctx context.Context) (context.Context, error)

WithAsyncMode returns a context that allows execution of query in async mode

func WithMultiStatement

func WithMultiStatement(ctx context.Context, num int) (context.Context, error)

WithMultiStatement returns a context that allows the user to execute the desired number of sql queries in one query

func WithQueryIDChan

func WithQueryIDChan(ctx context.Context, c chan<- string) context.Context

WithQueryIDChan returns a context that contains the channel to receive the query ID

func WithRequestID

func WithRequestID(ctx context.Context, requestID string) context.Context

WithRequestID returns a new context with the specified snowflake request id

Types

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
)

func (AuthType) String

func (authType AuthType) String() string

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

	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

	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

	PrivateKey *rsa.PrivateKey // Private key used to sign JWT

	Transporter http.RoundTripper // RoundTripper to intercept HTTP requests and responses
}

Config is a set of configuration parameters

func ParseDSN

func ParseDSN(dsn string) (cfg *Config, err error)

ParseDSN parses the DSN string to a 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 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.

func (Connector) Connect

func (t Connector) Connect(ctx context.Context) (driver.Conn, error)

Connect creates a new connection.

func (Connector) Driver

func (t Connector) Driver() driver.Driver

Driver creates a new driver.

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
	WithContext(ctx context.Context) *rlog.Entry
	SetOutput(output io.Writer)
}

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

func GetLogger

func GetLogger() SFLogger

GetLogger return logger that is not public

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

func (d SnowflakeDriver) OpenWithConfig(ctx context.Context, config Config) (driver.Conn, error)

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 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 SnowflakeResult

type SnowflakeResult interface {
	GetQueryID() string
	GetStatus() queryStatus
}

SnowflakeResult provides the associated query ID

type SnowflakeRows

type SnowflakeRows struct {
	RowType         []execResponseRowType
	ChunkDownloader *snowflakeChunkDownloader
	QueryID         string
	// contains filtered or unexported fields
}

func (*SnowflakeRows) Close

func (rows *SnowflakeRows) Close() (err error)

func (*SnowflakeRows) ColumnTypeDatabaseTypeName

func (rows *SnowflakeRows) ColumnTypeDatabaseTypeName(index int) string

ColumnTypeDatabaseTypeName returns the database column name.

func (*SnowflakeRows) ColumnTypeLength

func (rows *SnowflakeRows) ColumnTypeLength(index int) (length int64, ok bool)

ColumnTypeLength returns the length of the column

func (*SnowflakeRows) ColumnTypeNullable

func (rows *SnowflakeRows) ColumnTypeNullable(index int) (nullable, ok bool)

func (*SnowflakeRows) ColumnTypePrecisionScale

func (rows *SnowflakeRows) ColumnTypePrecisionScale(index int) (precision, scale int64, ok bool)

func (*SnowflakeRows) ColumnTypeScanType

func (rows *SnowflakeRows) ColumnTypeScanType(index int) reflect.Type

func (*SnowflakeRows) Columns

func (rows *SnowflakeRows) Columns() []string

func (*SnowflakeRows) GetQueryID

func (rows *SnowflakeRows) GetQueryID() string

func (*SnowflakeRows) GetStatus

func (rows *SnowflakeRows) GetStatus() queryStatus

func (*SnowflakeRows) HasNextResultSet

func (rows *SnowflakeRows) HasNextResultSet() bool

func (*SnowflakeRows) Next

func (rows *SnowflakeRows) Next(dest []driver.Value) (err error)

func (*SnowflakeRows) NextResultSet

func (rows *SnowflakeRows) NextResultSet() error