Documentation ¶
Overview ¶
Package pgx is a PostgreSQL database driver.
pgx provides lower level access to PostgreSQL than the standard database/sql. It remains as similar to the database/sql interface as possible while providing better speed and access to PostgreSQL specific features. Import github.com/jackc/pgx/stdlib to use pgx as a database/sql compatible driver.
Query Interface ¶
pgx implements Query and Scan in the familiar database/sql style.
var sum int32 // Send the query to the server. The returned rows MUST be closed // before conn can be used again. rows, err := conn.Query("select generate_series(1,$1)", 10) if err != nil { return err } // rows.Close is called by rows.Next when all rows are read // or an error occurs in Next or Scan. So it may optionally be // omitted if nothing in the rows.Next loop can panic. It is // safe to close rows multiple times. defer rows.Close() // Iterate through the result set for rows.Next() { var n int32 err = rows.Scan(&n) if err != nil { return err } sum += n } // Any errors encountered by rows.Next or rows.Scan will be returned here if rows.Err() != nil { return err } // No errors found - do something with sum
pgx also implements QueryRow in the same style as database/sql.
var name string var weight int64 err := conn.QueryRow("select name, weight from widgets where id=$1", 42).Scan(&name, &weight) if err != nil { return err }
Use Exec to execute a query that does not return a result set.
commandTag, err := conn.Exec("delete from widgets where id=$1", 42) if err != nil { return err } if commandTag.RowsAffected() != 1 { return errors.New("No row found to delete") }
Connection Pool ¶
Connection pool usage is explicit and configurable. In pgx, a connection can be created and managed directly, or a connection pool with a configurable maximum connections can be used. The connection pool offers an after connect hook that allows every connection to be automatically setup before being made available in the connection pool.
It delegates methods such as QueryRow to an automatically checked out and released connection so you can avoid manually acquiring and releasing connections when you do not need that level of control.
var name string var weight int64 err := pool.QueryRow("select name, weight from widgets where id=$1", 42).Scan(&name, &weight) if err != nil { return err }
Base Type Mapping ¶
pgx maps between all common base types directly between Go and PostgreSQL. In particular:
Go PostgreSQL ----------------------- string varchar text // Integers are automatically be converted to any other integer type if // it can be done without overflow or underflow. int8 int16 smallint int32 int int64 bigint int uint8 uint16 uint32 uint64 uint // Floats are strict and do not automatically convert like integers. float32 float4 float64 float8 time.Time date timestamp timestamptz []byte bytea
Null Mapping ¶
pgx can map nulls in two ways. The first is package pgtype provides types that have a data field and a status field. They work in a similar fashion to database/sql. The second is to use a pointer to a pointer.
var foo pgtype.Varchar var bar *string err := conn.QueryRow("select foo, bar from widgets where id=$1", 42).Scan(&a, &b) if err != nil { return err }
Array Mapping ¶
pgx maps between int16, int32, int64, float32, float64, and string Go slices and the equivalent PostgreSQL array type. Go slices of native types do not support nulls, so if a PostgreSQL array that contains a null is read into a native Go slice an error will occur. The pgtype package includes many more array types for PostgreSQL types that do not directly map to native Go types.
JSON and JSONB Mapping ¶
pgx includes built-in support to marshal and unmarshal between Go types and the PostgreSQL JSON and JSONB.
Inet and CIDR Mapping ¶
pgx encodes from net.IPNet to and from inet and cidr PostgreSQL types. In addition, as a convenience pgx will encode from a net.IP; it will assume a /32 netmask for IPv4 and a /128 for IPv6.
Custom Type Support ¶
pgx includes support for the common data types like integers, floats, strings, dates, and times that have direct mappings between Go and SQL. In addition, pgx uses the github.com/jackc/pgx/pgtype library to support more types. See documention for that library for instructions on how to implement custom types.
See example_custom_type_test.go for an example of a custom type for the PostgreSQL point type.
pgx also includes support for custom types implementing the database/sql.Scanner and database/sql/driver.Valuer interfaces.
Raw Bytes Mapping ¶
[]byte passed as arguments to Query, QueryRow, and Exec are passed unmodified to PostgreSQL.
Transactions ¶
Transactions are started by calling Begin or BeginEx. The BeginEx variant can create a transaction with a specified isolation level.
tx, err := conn.Begin() if err != nil { return err } // Rollback is safe to call even if the tx is already closed, so if // the tx commits successfully, this is a no-op defer tx.Rollback() _, err = tx.Exec("insert into foo(id) values (1)") if err != nil { return err } err = tx.Commit() if err != nil { return err }
Copy Protocol ¶
Use CopyFrom to efficiently insert multiple rows at a time using the PostgreSQL copy protocol. CopyFrom accepts a CopyFromSource interface. If the data is already in a [][]interface{} use CopyFromRows to wrap it in a CopyFromSource interface. Or implement CopyFromSource to avoid buffering the entire data set in memory.
rows := [][]interface{}{ {"John", "Smith", int32(36)}, {"Jane", "Doe", int32(29)}, } copyCount, err := conn.CopyFrom( pgx.Identifier{"people"}, []string{"first_name", "last_name", "age"}, pgx.CopyFromRows(rows), )
CopyFrom can be faster than an insert with as few as 5 rows.
Listen and Notify ¶
pgx can listen to the PostgreSQL notification system with the WaitForNotification function. It takes a maximum time to wait for a notification.
err := conn.Listen("channelname") if err != nil { return nil } if notification, err := conn.WaitForNotification(time.Second); err != nil { // do something with notification }
TLS ¶
The pgx ConnConfig struct has a TLSConfig field. If this field is nil, then TLS will be disabled. If it is present, then it will be used to configure the TLS connection. This allows total configuration of the TLS connection.
Logging ¶
pgx defines a simple logger interface. Connections optionally accept a logger that satisfies this interface. Set LogLevel to control logging verbosity. Adapters for github.com/inconshreveable/log15, github.com/sirupsen/logrus, and the testing log are provided in the log directory.
Index ¶
- Constants
- Variables
- func FormatLSN(lsn uint64) string
- func ParseLSN(lsn string) (outputLsn uint64, err error)
- type Batch
- func (b *Batch) Close() (err error)
- func (b *Batch) Conn() *Conn
- func (b *Batch) ExecResults() (CommandTag, error)
- func (b *Batch) QueryResults() (*Rows, error)
- func (b *Batch) QueryRowResults() *Row
- func (b *Batch) Queue(query string, arguments []interface{}, parameterOIDs []pgtype.OID, ...)
- func (b *Batch) Send(ctx context.Context, txOptions *TxOptions) error
- type CommandTag
- type Conn
- func (c *Conn) Begin() (*Tx, error)
- func (c *Conn) BeginBatch() *Batch
- func (c *Conn) BeginEx(ctx context.Context, txOptions *TxOptions) (*Tx, error)
- func (c *Conn) CauseOfDeath() error
- func (c *Conn) Close() (err error)
- func (c *Conn) CopyFrom(tableName Identifier, columnNames []string, rowSrc CopyFromSource) (int, error)
- func (c *Conn) Deallocate(name string) error
- func (c *Conn) Exec(sql string, arguments ...interface{}) (commandTag CommandTag, err error)
- func (c *Conn) ExecEx(ctx context.Context, sql string, options *QueryExOptions, ...) (CommandTag, error)
- func (c *Conn) IsAlive() bool
- func (c *Conn) Listen(channel string) error
- func (c *Conn) PID() uint32
- func (c *Conn) Ping(ctx context.Context) error
- func (c *Conn) Prepare(name, sql string) (ps *PreparedStatement, err error)
- func (c *Conn) PrepareEx(ctx context.Context, name, sql string, opts *PrepareExOptions) (ps *PreparedStatement, err error)
- func (c *Conn) Query(sql string, args ...interface{}) (*Rows, error)
- func (c *Conn) QueryEx(ctx context.Context, sql string, options *QueryExOptions, args ...interface{}) (rows *Rows, err error)
- func (c *Conn) QueryRow(sql string, args ...interface{}) *Row
- func (c *Conn) QueryRowEx(ctx context.Context, sql string, options *QueryExOptions, args ...interface{}) *Row
- func (c *Conn) SetLogLevel(lvl int) (int, error)
- func (c *Conn) SetLogger(logger Logger) Logger
- func (c *Conn) Unlisten(channel string) error
- func (c *Conn) WaitForNotification(ctx context.Context) (notification *Notification, err error)
- type ConnConfig
- type ConnPool
- func (p *ConnPool) Acquire() (*Conn, error)
- func (p *ConnPool) Begin() (*Tx, error)
- func (p *ConnPool) BeginBatch() *Batch
- func (p *ConnPool) BeginEx(ctx context.Context, txOptions *TxOptions) (*Tx, error)
- func (p *ConnPool) Close()
- func (p *ConnPool) CopyFrom(tableName Identifier, columnNames []string, rowSrc CopyFromSource) (int, error)
- func (p *ConnPool) Deallocate(name string) (err error)
- func (p *ConnPool) Exec(sql string, arguments ...interface{}) (commandTag CommandTag, err error)
- func (p *ConnPool) ExecEx(ctx context.Context, sql string, options *QueryExOptions, ...) (commandTag CommandTag, err error)
- func (p *ConnPool) Prepare(name, sql string) (*PreparedStatement, error)
- func (p *ConnPool) PrepareEx(ctx context.Context, name, sql string, opts *PrepareExOptions) (*PreparedStatement, error)
- func (p *ConnPool) Query(sql string, args ...interface{}) (*Rows, error)
- func (p *ConnPool) QueryEx(ctx context.Context, sql string, options *QueryExOptions, args ...interface{}) (*Rows, error)
- func (p *ConnPool) QueryRow(sql string, args ...interface{}) *Row
- func (p *ConnPool) QueryRowEx(ctx context.Context, sql string, options *QueryExOptions, args ...interface{}) *Row
- func (p *ConnPool) Release(conn *Conn)
- func (p *ConnPool) Reset()
- func (p *ConnPool) Stat() (s ConnPoolStat)
- type ConnPoolConfig
- type ConnPoolStat
- type CopyFromSource
- type DialFunc
- type FieldDescription
- type Identifier
- type LargeObject
- func (o *LargeObject) Close() error
- func (o *LargeObject) Read(p []byte) (int, error)
- func (o *LargeObject) Seek(offset int64, whence int) (n int64, err error)
- func (o *LargeObject) Tell() (n int64, err error)
- func (o *LargeObject) Truncate(size int64) (err error)
- func (o *LargeObject) Write(p []byte) (int, error)
- type LargeObjectMode
- type LargeObjects
- type LogLevel
- type Logger
- type Notice
- type NoticeHandler
- type Notification
- type PgError
- type PrepareExOptions
- type PreparedStatement
- type ProtocolError
- type QueryArgs
- type QueryExOptions
- type ReplicationConn
- func (rc *ReplicationConn) CauseOfDeath() error
- func (rc *ReplicationConn) Close() error
- func (rc *ReplicationConn) CreateReplicationSlot(slotName, outputPlugin string) (err error)
- func (rc *ReplicationConn) CreateReplicationSlotEx(slotName, outputPlugin string) (consistentPoint string, snapshotName string, err error)
- func (rc *ReplicationConn) DropReplicationSlot(slotName string) (err error)
- func (rc *ReplicationConn) IdentifySystem() (r *Rows, err error)
- func (rc *ReplicationConn) IsAlive() bool
- func (rc *ReplicationConn) SendStandbyStatus(k *StandbyStatus) (err error)
- func (rc *ReplicationConn) StartReplication(slotName string, startLsn uint64, timeline int64, pluginArguments ...string) (err error)
- func (rc *ReplicationConn) TimelineHistory(timeline int) (r *Rows, err error)
- func (rc *ReplicationConn) WaitForReplicationMessage(ctx context.Context) (*ReplicationMessage, error)
- type ReplicationMessage
- type Row
- type Rows
- type SerializationError
- type ServerHeartbeat
- type StandbyStatus
- type Tx
- func (tx *Tx) BeginBatch() *Batch
- func (tx *Tx) Commit() error
- func (tx *Tx) CommitEx(ctx context.Context) error
- func (tx *Tx) CopyFrom(tableName Identifier, columnNames []string, rowSrc CopyFromSource) (int, error)
- func (tx *Tx) Err() error
- func (tx *Tx) Exec(sql string, arguments ...interface{}) (commandTag CommandTag, err error)
- func (tx *Tx) ExecEx(ctx context.Context, sql string, options *QueryExOptions, ...) (commandTag CommandTag, err error)
- func (tx *Tx) LargeObjects() (*LargeObjects, error)
- func (tx *Tx) Prepare(name, sql string) (*PreparedStatement, error)
- func (tx *Tx) PrepareEx(ctx context.Context, name, sql string, opts *PrepareExOptions) (*PreparedStatement, error)
- func (tx *Tx) Query(sql string, args ...interface{}) (*Rows, error)
- func (tx *Tx) QueryEx(ctx context.Context, sql string, options *QueryExOptions, args ...interface{}) (*Rows, error)
- func (tx *Tx) QueryRow(sql string, args ...interface{}) *Row
- func (tx *Tx) QueryRowEx(ctx context.Context, sql string, options *QueryExOptions, args ...interface{}) *Row
- func (tx *Tx) Rollback() error
- func (tx *Tx) RollbackEx(ctx context.Context) error
- func (tx *Tx) Status() int8
- type TxAccessMode
- type TxDeferrableMode
- type TxIsoLevel
- type TxOptions
- type WalMessage
Constants ¶
const ( LogLevelTrace = 6 LogLevelDebug = 5 LogLevelInfo = 4 LogLevelWarn = 3 LogLevelError = 2 LogLevelNone = 1 )
The values for log levels are chosen such that the zero value means that no log level was specified.
const ( Serializable = TxIsoLevel("serializable") RepeatableRead = TxIsoLevel("repeatable read") ReadCommitted = TxIsoLevel("read committed") ReadUncommitted = TxIsoLevel("read uncommitted") )
Transaction isolation levels
const ( ReadWrite = TxAccessMode("read write") ReadOnly = TxAccessMode("read only") )
Transaction access modes
const ( Deferrable = TxDeferrableMode("deferrable") NotDeferrable = TxDeferrableMode("not deferrable") )
Transaction deferrable modes
const ( TxStatusInProgress = 0 TxStatusCommitFailure = -1 TxStatusRollbackFailure = -2 TxStatusCommitSuccess = 1 TxStatusRollbackSuccess = 2 )
const ( TextFormatCode = 0 BinaryFormatCode = 1 )
PostgreSQL format codes
Variables ¶
var ErrAcquireTimeout = errors.New("timeout acquiring connection from pool")
ErrAcquireTimeout occurs when an attempt to acquire a connection times out.
var ErrClosedPool = errors.New("cannot acquire from closed pool")
ErrClosedPool occurs on an attempt to acquire a connection from a closed pool.
var ErrConnBusy = errors.New("conn is busy")
ErrConnBusy occurs when the connection is busy (for example, in the middle of reading query results) and another action is attempted.
var ErrDeadConn = errors.New("conn is dead")
ErrDeadConn occurs on an attempt to use a dead connection
var ErrInvalidLogLevel = errors.New("invalid log level")
ErrInvalidLogLevel occurs on attempt to set an invalid log level.
var ErrNoRows = errors.New("no rows in result set")
ErrNoRows occurs when rows are expected but none are returned.
var ErrTLSRefused = errors.New("server refused TLS connection")
ErrTLSRefused occurs when the connection attempt requires TLS and the PostgreSQL server refuses to use TLS
var ErrTxClosed = errors.New("tx is closed")
var ErrTxCommitRollback = errors.New("commit unexpectedly resulted in rollback")
ErrTxCommitRollback occurs when an error has occurred in a transaction and Commit() is called. PostgreSQL accepts COMMIT on aborted transactions, but it is treated as ROLLBACK.
Functions ¶
Types ¶
type Batch ¶
type Batch struct {
// contains filtered or unexported fields
}
Batch queries are a way of bundling multiple queries together to avoid unnecessary network round trips.
func (*Batch) Close ¶
Close closes the batch operation. Any error that occured during a batch operation may have made it impossible to resyncronize the connection with the server. In this case the underlying connection will have been closed.
func (*Batch) ExecResults ¶
func (b *Batch) ExecResults() (CommandTag, error)
ExecResults reads the results from the next query in the batch as if the query has been sent with Exec.
func (*Batch) QueryResults ¶
QueryResults reads the results from the next query in the batch as if the query has been sent with Query.
func (*Batch) QueryRowResults ¶
QueryRowResults reads the results from the next query in the batch as if the query has been sent with QueryRow.
func (*Batch) Queue ¶
func (b *Batch) Queue(query string, arguments []interface{}, parameterOIDs []pgtype.OID, resultFormatCodes []int16)
Queue queues a query to batch b. parameterOIDs are required if there are parameters and query is not the name of a prepared statement. resultFormatCodes are required if there is a result.
func (*Batch) Send ¶
Send sends all queued queries to the server at once. If the batch is created from a conn Object then All queries are wrapped in a transaction. The transaction can optionally be configured with txOptions. The context is in effect until the Batch is closed.
Warning: Send writes all queued queries before reading any results. This can cause a deadlock if an excessive number of queries are queued. It is highly advisable to use a timeout context to protect against this possibility. Unfortunately, this excessive number can vary based on operating system, connection type (TCP or Unix domain socket), and type of query. Unix domain sockets seem to be much more susceptible to this issue than TCP connections. However, it usually is at least several thousand.
The deadlock occurs when the batched queries to be sent are so large that the PostgreSQL server cannot receive it all at once. PostgreSQL received some of the queued queries and starts executing them. As PostgreSQL executes the queries it sends responses back. pgx will not read any of these responses until it has finished sending. Therefore, if all network buffers are full pgx will not be able to finish sending the queries and PostgreSQL will not be able to finish sending the responses.
type CommandTag ¶
type CommandTag string
CommandTag is the result of an Exec function
func (CommandTag) RowsAffected ¶
func (ct CommandTag) RowsAffected() int64
RowsAffected returns the number of rows affected. If the CommandTag was not for a row affecting command (such as "CREATE TABLE") then it returns 0
type Conn ¶
type Conn struct { RuntimeParams map[string]string // parameters that have been reported by the server ConnInfo *pgtype.ConnInfo // contains filtered or unexported fields }
Conn is a PostgreSQL connection handle. It is not safe for concurrent usage. Use ConnPool to manage access to multiple database connections from multiple goroutines.
func Connect ¶
func Connect(config ConnConfig) (c *Conn, err error)
Connect establishes a connection with a PostgreSQL server using config. config.Host must be specified. config.User will default to the OS user name. Other config fields are optional.
func (*Conn) Begin ¶
Begin starts a transaction with the default transaction mode for the current connection. To use a specific transaction mode see BeginEx.
func (*Conn) BeginBatch ¶
BeginBatch returns a *Batch query for c.
func (*Conn) BeginEx ¶
BeginEx starts a transaction with txOptions determining the transaction mode. Unlike database/sql, the context only affects the begin command. i.e. there is no auto-rollback on context cancelation.
func (*Conn) CauseOfDeath ¶
func (*Conn) Close ¶
Close closes a connection. It is safe to call Close on a already closed connection.
func (*Conn) CopyFrom ¶
func (c *Conn) CopyFrom(tableName Identifier, columnNames []string, rowSrc CopyFromSource) (int, error)
CopyFrom uses the PostgreSQL copy protocol to perform bulk data insertion. It returns the number of rows copied and an error.
CopyFrom requires all values use the binary format. Almost all types implemented by pgx use the binary format by default. Types implementing Encoder can only be used if they encode to the binary format.
func (*Conn) Deallocate ¶
Deallocate released a prepared statement
func (*Conn) Exec ¶
func (c *Conn) Exec(sql string, arguments ...interface{}) (commandTag CommandTag, err error)
Exec executes sql. sql can be either a prepared statement name or an SQL string. arguments should be referenced positionally from the sql string as $1, $2, etc.
func (*Conn) ExecEx ¶
func (c *Conn) ExecEx(ctx context.Context, sql string, options *QueryExOptions, arguments ...interface{}) (CommandTag, error)
func (*Conn) Prepare ¶
func (c *Conn) Prepare(name, sql string) (ps *PreparedStatement, err error)
Prepare creates a prepared statement with name and sql. sql can contain placeholders for bound parameters. These placeholders are referenced positional as $1, $2, etc.
Prepare is idempotent; i.e. it is safe to call Prepare multiple times with the same name and sql arguments. This allows a code path to Prepare and Query/Exec without concern for if the statement has already been prepared.
func (*Conn) PrepareEx ¶
func (c *Conn) PrepareEx(ctx context.Context, name, sql string, opts *PrepareExOptions) (ps *PreparedStatement, err error)
PrepareEx creates a prepared statement with name and sql. sql can contain placeholders for bound parameters. These placeholders are referenced positional as $1, $2, etc. It defers from Prepare as it allows additional options (such as parameter OIDs) to be passed via struct
PrepareEx is idempotent; i.e. it is safe to call PrepareEx multiple times with the same name and sql arguments. This allows a code path to PrepareEx and Query/Exec without concern for if the statement has already been prepared.
func (*Conn) Query ¶
Query executes sql with args. If there is an error the returned *Rows will be returned in an error state. So it is allowed to ignore the error returned from Query and handle it in *Rows.
func (*Conn) QueryRow ¶
QueryRow is a convenience wrapper over Query. Any error that occurs while querying is deferred until calling Scan on the returned *Row. That *Row will error with ErrNoRows if no rows are returned.
func (*Conn) QueryRowEx ¶
func (*Conn) SetLogLevel ¶
SetLogLevel replaces the current log level and returns the previous log level.
func (*Conn) WaitForNotification ¶
func (c *Conn) WaitForNotification(ctx context.Context) (notification *Notification, err error)
WaitForNotification waits for a PostgreSQL notification.
type ConnConfig ¶
type ConnConfig struct { Host string // host (e.g. localhost) or path to unix domain socket directory (e.g. /private/tmp) Port uint16 // default: 5432 Database string User string // default: OS user name Password string TLSConfig *tls.Config // config for TLS connection -- nil disables TLS UseFallbackTLS bool // Try FallbackTLSConfig if connecting with TLSConfig fails. Used for preferring TLS, but allowing unencrypted, or vice-versa FallbackTLSConfig *tls.Config // config for fallback TLS connection (only used if UseFallBackTLS is true)-- nil disables TLS Logger Logger LogLevel int Dial DialFunc RuntimeParams map[string]string // Run-time parameters to set on connection as session default values (e.g. search_path or application_name) OnNotice NoticeHandler // Callback function called when a notice response is received. CustomConnInfo func(*Conn) (*pgtype.ConnInfo, error) // Callback function to implement connection strategies for different backends. crate, pgbouncer, pgpool, etc. // PreferSimpleProtocol disables implicit prepared statement usage. By default // pgx automatically uses the unnamed prepared statement for Query and // QueryRow. It also uses a prepared statement when Exec has arguments. This // can improve performance due to being able to use the binary format. It also // does not rely on client side parameter sanitization. However, it does incur // two round-trips per query and may be incompatible proxies such as // PGBouncer. Setting PreferSimpleProtocol causes the simple protocol to be // used by default. The same functionality can be controlled on a per query // basis by setting QueryExOptions.SimpleProtocol. PreferSimpleProtocol bool }
ConnConfig contains all the options used to establish a connection.
func ParseConnectionString ¶
func ParseConnectionString(s string) (ConnConfig, error)
ParseConnectionString parses either a URI or a DSN connection string. see ParseURI and ParseDSN for details.
func ParseDSN ¶
func ParseDSN(s string) (ConnConfig, error)
ParseDSN parses a database DSN (data source name) into a ConnConfig
e.g. ParseDSN("user=username password=password host=1.2.3.4 port=5432 dbname=mydb sslmode=disable")
Any options not used by the connection process are parsed into ConnConfig.RuntimeParams.
e.g. ParseDSN("application_name=pgxtest search_path=admin user=username password=password host=1.2.3.4 dbname=mydb")
ParseDSN tries to match libpq behavior with regard to sslmode. See comments for ParseEnvLibpq for more information on the security implications of sslmode options.
func ParseEnvLibpq ¶
func ParseEnvLibpq() (ConnConfig, error)
ParseEnvLibpq parses the environment like libpq does into a ConnConfig
See http://www.postgresql.org/docs/9.4/static/libpq-envars.html for details on the meaning of environment variables.
ParseEnvLibpq currently recognizes the following environment variables: PGHOST PGPORT PGDATABASE PGUSER PGPASSWORD PGSSLMODE PGAPPNAME PGCONNECT_TIMEOUT
Important TLS Security Notes: ParseEnvLibpq tries to match libpq behavior with regard to PGSSLMODE. This includes defaulting to "prefer" behavior if no environment variable is set.
See http://www.postgresql.org/docs/9.4/static/libpq-ssl.html#LIBPQ-SSL-PROTECTION for details on what level of security each sslmode provides.
"verify-ca" mode currently is treated as "verify-full". e.g. It has stronger security guarantees than it would with libpq. Do not rely on this behavior as it may be possible to match libpq in the future. If you need full security use "verify-full".
Several of the PGSSLMODE options (including the default behavior of "prefer") will set UseFallbackTLS to true and FallbackTLSConfig to a disabled or weakened TLS mode. This means that if ParseEnvLibpq is used, but TLSConfig is later set from a different source that UseFallbackTLS MUST be set false to avoid the possibility of falling back to weaker or disabled security.
func ParseURI ¶
func ParseURI(uri string) (ConnConfig, error)
ParseURI parses a database URI into ConnConfig
Query parameters not used by the connection process are parsed into ConnConfig.RuntimeParams.
func (ConnConfig) Merge ¶
func (old ConnConfig) Merge(other ConnConfig) ConnConfig
Merge returns a new ConnConfig with the attributes of old and other combined. When an attribute is set on both, other takes precedence.
As a security precaution, if the other TLSConfig is nil, all old TLS attributes will be preserved.
type ConnPool ¶
type ConnPool struct {
// contains filtered or unexported fields
}
func NewConnPool ¶
func NewConnPool(config ConnPoolConfig) (p *ConnPool, err error)
NewConnPool creates a new ConnPool. config.ConnConfig is passed through to Connect directly.
func (*ConnPool) Begin ¶
Begin acquires a connection and begins a transaction on it. When the transaction is closed the connection will be automatically released.
func (*ConnPool) BeginBatch ¶
BeginBatch acquires a connection and begins a batch on that connection. When *Batch is finished, the connection is released automatically.
func (*ConnPool) BeginEx ¶
BeginEx acquires a connection and starts a transaction with txOptions determining the transaction mode. When the transaction is closed the connection will be automatically released.
func (*ConnPool) Close ¶
func (p *ConnPool) Close()
Close ends the use of a connection pool. It prevents any new connections from being acquired and closes available underlying connections. Any acquired connections will be closed when they are released.
func (*ConnPool) CopyFrom ¶
func (p *ConnPool) CopyFrom(tableName Identifier, columnNames []string, rowSrc CopyFromSource) (int, error)
CopyFrom acquires a connection, delegates the call to that connection, and releases the connection
func (*ConnPool) Deallocate ¶
Deallocate releases a prepared statement from all connections in the pool.
func (*ConnPool) Exec ¶
func (p *ConnPool) Exec(sql string, arguments ...interface{}) (commandTag CommandTag, err error)
Exec acquires a connection, delegates the call to that connection, and releases the connection
func (*ConnPool) ExecEx ¶
func (p *ConnPool) ExecEx(ctx context.Context, sql string, options *QueryExOptions, arguments ...interface{}) (commandTag CommandTag, err error)
func (*ConnPool) Prepare ¶
func (p *ConnPool) Prepare(name, sql string) (*PreparedStatement, error)
Prepare creates a prepared statement on a connection in the pool to test the statement is valid. If it succeeds all connections accessed through the pool will have the statement available.
Prepare creates a prepared statement with name and sql. sql can contain placeholders for bound parameters. These placeholders are referenced positional as $1, $2, etc.
Prepare is idempotent; i.e. it is safe to call Prepare multiple times with the same name and sql arguments. This allows a code path to Prepare and Query/Exec/PrepareEx without concern for if the statement has already been prepared.
func (*ConnPool) PrepareEx ¶
func (p *ConnPool) PrepareEx(ctx context.Context, name, sql string, opts *PrepareExOptions) (*PreparedStatement, error)
PrepareEx creates a prepared statement on a connection in the pool to test the statement is valid. If it succeeds all connections accessed through the pool will have the statement available.
PrepareEx creates a prepared statement with name and sql. sql can contain placeholders for bound parameters. These placeholders are referenced positional as $1, $2, etc. It defers from Prepare as it allows additional options (such as parameter OIDs) to be passed via struct
PrepareEx is idempotent; i.e. it is safe to call PrepareEx multiple times with the same name and sql arguments. This allows a code path to PrepareEx and Query/Exec/Prepare without concern for if the statement has already been prepared.
func (*ConnPool) Query ¶
Query acquires a connection and delegates the call to that connection. When *Rows are closed, the connection is released automatically.
func (*ConnPool) QueryRow ¶
QueryRow acquires a connection and delegates the call to that connection. The connection is released automatically after Scan is called on the returned *Row.
func (*ConnPool) QueryRowEx ¶
func (*ConnPool) Reset ¶
func (p *ConnPool) Reset()
Reset closes all open connections, but leaves the pool open. It is intended for use when an error is detected that would disrupt all connections (such as a network interruption or a server state change).
It is safe to reset a pool while connections are checked out. Those connections will be closed when they are returned to the pool.
func (*ConnPool) Stat ¶
func (p *ConnPool) Stat() (s ConnPoolStat)
Stat returns connection pool statistics
type ConnPoolConfig ¶
type ConnPoolConfig struct { ConnConfig MaxConnections int // max simultaneous connections to use, default 5, must be at least 2 AfterConnect func(*Conn) error // function to call on every new connection AcquireTimeout time.Duration // max wait time when all connections are busy (0 means no timeout) }
type ConnPoolStat ¶
type CopyFromSource ¶
type CopyFromSource interface { // Next returns true if there is another row and makes the next row data // available to Values(). When there are no more rows available or an error // has occurred it returns false. Next() bool // Values returns the values for the current row. Values() ([]interface{}, error) // Err returns any error that has been encountered by the CopyFromSource. If // this is not nil *Conn.CopyFrom will abort the copy. Err() error }
CopyFromSource is the interface used by *Conn.CopyFrom as the source for copy data.
func CopyFromRows ¶
func CopyFromRows(rows [][]interface{}) CopyFromSource
CopyFromRows returns a CopyFromSource interface over the provided rows slice making it usable by *Conn.CopyFrom.
type FieldDescription ¶
type FieldDescription struct { Name string Table pgtype.OID AttributeNumber uint16 DataType pgtype.OID DataTypeSize int16 DataTypeName string Modifier uint32 FormatCode int16 }
func (FieldDescription) Length ¶
func (fd FieldDescription) Length() (int64, bool)
func (FieldDescription) PrecisionScale ¶
func (fd FieldDescription) PrecisionScale() (precision, scale int64, ok bool)
func (FieldDescription) Type ¶
func (fd FieldDescription) Type() reflect.Type
type Identifier ¶
type Identifier []string
Identifier a PostgreSQL identifier or name. Identifiers can be composed of multiple parts such as ["schema", "table"] or ["table", "column"].
func (Identifier) Sanitize ¶
func (ident Identifier) Sanitize() string
Sanitize returns a sanitized string safe for SQL interpolation.
type LargeObject ¶
type LargeObject struct {
// contains filtered or unexported fields
}
A LargeObject is a large object stored on the server. It is only valid within the transaction that it was initialized in. It implements these interfaces:
io.Writer io.Reader io.Seeker io.Closer
func (*LargeObject) Close ¶
func (o *LargeObject) Close() error
Close closees the large object descriptor.
func (*LargeObject) Read ¶
func (o *LargeObject) Read(p []byte) (int, error)
Read reads up to len(p) bytes into p returning the number of bytes read.
func (*LargeObject) Seek ¶
func (o *LargeObject) Seek(offset int64, whence int) (n int64, err error)
Seek moves the current location pointer to the new location specified by offset.
func (*LargeObject) Tell ¶
func (o *LargeObject) Tell() (n int64, err error)
Tell returns the current read or write location of the large object descriptor.
func (*LargeObject) Truncate ¶
func (o *LargeObject) Truncate(size int64) (err error)
Trunctes the large object to size.
type LargeObjectMode ¶
type LargeObjectMode int32
const ( LargeObjectModeWrite LargeObjectMode = 0x20000 LargeObjectModeRead LargeObjectMode = 0x40000 )
type LargeObjects ¶
type LargeObjects struct { // Has64 is true if the server is capable of working with 64-bit numbers Has64 bool // contains filtered or unexported fields }
LargeObjects is a structure used to access the large objects API. It is only valid within the transaction where it was created.
For more details see: http://www.postgresql.org/docs/current/static/largeobjects.html
func (*LargeObjects) Create ¶
Create creates a new large object. If id is zero, the server assigns an unused OID.
func (*LargeObjects) Open ¶
func (o *LargeObjects) Open(oid pgtype.OID, mode LargeObjectMode) (*LargeObject, error)
Open opens an existing large object with the given mode.
type LogLevel ¶
type LogLevel int
LogLevel represents the pgx logging level. See LogLevel* constants for possible values.
func LogLevelFromString ¶
LogLevelFromString converts log level string to constant
Valid levels:
trace debug info warn error none
type Logger ¶
type Logger interface { // Log a message at the given level with data key/value pairs. data may be nil. Log(level LogLevel, msg string, data map[string]interface{}) }
Logger is the interface used to get logging from pgx internals.
type Notice ¶
type Notice PgError
Notice represents a notice response message reported by the PostgreSQL server. Be aware that this is distinct from LISTEN/NOTIFY notification.
type NoticeHandler ¶
NoticeHandler is a function that can handle notices received from the PostgreSQL server. Notices can be received at any time, usually during handling of a query response. The *Conn is provided so the handler is aware of the origin of the notice, but it must not invoke any query method. Be aware that this is distinct from LISTEN/NOTIFY notification.
type Notification ¶
type Notification struct { PID uint32 // backend pid that sent the notification Channel string // channel from which notification was received Payload string }
Notification is a message received from the PostgreSQL LISTEN/NOTIFY system
type PgError ¶
type PgError struct { Severity string Code string Message string Detail string Hint string Position int32 InternalPosition int32 InternalQuery string Where string SchemaName string TableName string ColumnName string DataTypeName string ConstraintName string File string Line int32 Routine string }
PgError represents an error reported by the PostgreSQL server. See http://www.postgresql.org/docs/9.3/static/protocol-error-fields.html for detailed field description.
type PrepareExOptions ¶
PrepareExOptions is an option struct that can be passed to PrepareEx
type PreparedStatement ¶
type PreparedStatement struct { Name string SQL string FieldDescriptions []FieldDescription ParameterOIDs []pgtype.OID }
PreparedStatement is a description of a prepared statement
type ProtocolError ¶
type ProtocolError string
ProtocolError occurs when unexpected data is received from PostgreSQL
func (ProtocolError) Error ¶
func (e ProtocolError) Error() string
type QueryArgs ¶
type QueryArgs []interface{}
QueryArgs is a container for arguments to an SQL query. It is helpful when building SQL statements where the number of arguments is variable.
type QueryExOptions ¶
type ReplicationConn ¶
type ReplicationConn struct {
// contains filtered or unexported fields
}
func ReplicationConnect ¶
func ReplicationConnect(config ConnConfig) (r *ReplicationConn, err error)
func (*ReplicationConn) CauseOfDeath ¶
func (rc *ReplicationConn) CauseOfDeath() error
func (*ReplicationConn) Close ¶
func (rc *ReplicationConn) Close() error
func (*ReplicationConn) CreateReplicationSlot ¶
func (rc *ReplicationConn) CreateReplicationSlot(slotName, outputPlugin string) (err error)
Create the replication slot, using the given name and output plugin.
func (*ReplicationConn) CreateReplicationSlotEx ¶
func (rc *ReplicationConn) CreateReplicationSlotEx(slotName, outputPlugin string) (consistentPoint string, snapshotName string, err error)
Create the replication slot, using the given name and output plugin, and return the consistent_point and snapshot_name values.
func (*ReplicationConn) DropReplicationSlot ¶
func (rc *ReplicationConn) DropReplicationSlot(slotName string) (err error)
Drop the replication slot for the given name
func (*ReplicationConn) IdentifySystem ¶
func (rc *ReplicationConn) IdentifySystem() (r *Rows, err error)
Execute the "IDENTIFY_SYSTEM" command as documented here: https://www.postgresql.org/docs/9.5/static/protocol-replication.html
This will return (if successful) a result set that has a single row that contains the systemid, current timeline, xlogpos and database name.
NOTE: Because this is a replication mode connection, we don't have type names, so the field descriptions in the result will have only OIDs and no DataTypeName values
func (*ReplicationConn) IsAlive ¶
func (rc *ReplicationConn) IsAlive() bool
func (*ReplicationConn) SendStandbyStatus ¶
func (rc *ReplicationConn) SendStandbyStatus(k *StandbyStatus) (err error)
Send standby status to the server, which both acts as a keepalive message to the server, as well as carries the WAL position of the client, which then updates the server's replication slot position.
func (*ReplicationConn) StartReplication ¶
func (rc *ReplicationConn) StartReplication(slotName string, startLsn uint64, timeline int64, pluginArguments ...string) (err error)
Start a replication connection, sending WAL data to the given replication receiver. This function wraps a START_REPLICATION command as documented here: https://www.postgresql.org/docs/9.5/static/protocol-replication.html
Once started, the client needs to invoke WaitForReplicationMessage() in order to fetch the WAL and standby status. Also, it is the responsibility of the caller to periodically send StandbyStatus messages to update the replication slot position.
This function assumes that slotName has already been created. In order to omit the timeline argument pass a -1 for the timeline to get the server default behavior.
func (*ReplicationConn) TimelineHistory ¶
func (rc *ReplicationConn) TimelineHistory(timeline int) (r *Rows, err error)
Execute the "TIMELINE_HISTORY" command as documented here: https://www.postgresql.org/docs/9.5/static/protocol-replication.html
This will return (if successful) a result set that has a single row that contains the filename of the history file and the content of the history file. If called for timeline 1, typically this will generate an error that the timeline history file does not exist.
NOTE: Because this is a replication mode connection, we don't have type names, so the field descriptions in the result will have only OIDs and no DataTypeName values
func (*ReplicationConn) WaitForReplicationMessage ¶
func (rc *ReplicationConn) WaitForReplicationMessage(ctx context.Context) (*ReplicationMessage, error)
Wait for a single replication message.
Properly using this requires some knowledge of the postgres replication mechanisms, as the client can receive both WAL data (the ultimate payload) and server heartbeat updates. The caller also must send standby status updates in order to keep the connection alive and working.
This returns the context error when there is no replication message before the context is canceled.
type ReplicationMessage ¶
type ReplicationMessage struct { WalMessage *WalMessage ServerHeartbeat *ServerHeartbeat }
The replication message wraps all possible messages from the server received during replication. At most one of the wal message or server heartbeat will be non-nil
type Rows ¶
type Rows struct {
// contains filtered or unexported fields
}
Rows is the result set returned from *Conn.Query. Rows must be closed before the *Conn can be used again. Rows are closed by explicitly calling Close(), calling Next() until it returns false, or when a fatal error occurs.
func (*Rows) Close ¶
func (rows *Rows) Close()
Close closes the rows, making the connection ready for use again. It is safe to call Close after rows is already closed.
func (*Rows) FieldDescriptions ¶
func (rows *Rows) FieldDescriptions() []FieldDescription
func (*Rows) Next ¶
Next prepares the next row for reading. It returns true if there is another row and false if no more rows are available. It automatically closes rows when all rows are read.
func (*Rows) Scan ¶
Scan reads the values from the current row into dest values positionally. dest can include pointers to core types, values implementing the Scanner interface, []byte, and nil. []byte will skip the decoding process and directly copy the raw bytes received from PostgreSQL. nil will skip the value entirely.
type SerializationError ¶
type SerializationError string
SerializationError occurs on failure to encode or decode a value
func (SerializationError) Error ¶
func (e SerializationError) Error() string
type ServerHeartbeat ¶
type ServerHeartbeat struct { // The current max wal position on the server, // used for lag tracking ServerWalEnd uint64 // The server time, in microseconds since jan 1 2000 ServerTime uint64 // If 1, the server is requesting a standby status message // to be sent immediately. ReplyRequested byte }
The server heartbeat is sent periodically from the server, including server status, and a reply request field
func (*ServerHeartbeat) String ¶
func (s *ServerHeartbeat) String() string
func (*ServerHeartbeat) Time ¶
func (s *ServerHeartbeat) Time() time.Time
type StandbyStatus ¶
type StandbyStatus struct { // The WAL position that's been locally written WalWritePosition uint64 // The WAL position that's been locally flushed WalFlushPosition uint64 // The WAL position that's been locally applied WalApplyPosition uint64 // The client time in microseconds since jan 1 2000 ClientTime uint64 // If 1, requests the server to immediately send a // server heartbeat ReplyRequested byte }
The standby status is the client side heartbeat sent to the postgresql server to track the client wal positions. For practical purposes, all wal positions are typically set to the same value.
func NewStandbyStatus ¶
func NewStandbyStatus(walPositions ...uint64) (status *StandbyStatus, err error)
Create a standby status struct, which sets all the WAL positions to the given wal position, and the client time to the current time. The wal positions are, in order: WalFlushPosition WalApplyPosition WalWritePosition
If only one position is provided, it will be used as the value for all 3 status fields. Note you must provide either 1 wal position, or all 3 in order to initialize the standby status.
type Tx ¶
type Tx struct {
// contains filtered or unexported fields
}
Tx represents a database transaction.
All Tx methods return ErrTxClosed if Commit or Rollback has already been called on the Tx.
func (*Tx) BeginBatch ¶
BeginBatch returns a *Batch query for tx. Since this *Batch is already part of a transaction it will not automatically be wrapped in a transaction.
func (*Tx) CopyFrom ¶
func (tx *Tx) CopyFrom(tableName Identifier, columnNames []string, rowSrc CopyFromSource) (int, error)
CopyFrom delegates to the underlying *Conn
func (*Tx) Exec ¶
func (tx *Tx) Exec(sql string, arguments ...interface{}) (commandTag CommandTag, err error)
Exec delegates to the underlying *Conn
func (*Tx) ExecEx ¶
func (tx *Tx) ExecEx(ctx context.Context, sql string, options *QueryExOptions, arguments ...interface{}) (commandTag CommandTag, err error)
ExecEx delegates to the underlying *Conn
func (*Tx) LargeObjects ¶
func (tx *Tx) LargeObjects() (*LargeObjects, error)
LargeObjects returns a LargeObjects instance for the transaction.
func (*Tx) Prepare ¶
func (tx *Tx) Prepare(name, sql string) (*PreparedStatement, error)
Prepare delegates to the underlying *Conn
func (*Tx) PrepareEx ¶
func (tx *Tx) PrepareEx(ctx context.Context, name, sql string, opts *PrepareExOptions) (*PreparedStatement, error)
PrepareEx delegates to the underlying *Conn
func (*Tx) QueryEx ¶
func (tx *Tx) QueryEx(ctx context.Context, sql string, options *QueryExOptions, args ...interface{}) (*Rows, error)
QueryEx delegates to the underlying *Conn
func (*Tx) QueryRowEx ¶
func (tx *Tx) QueryRowEx(ctx context.Context, sql string, options *QueryExOptions, args ...interface{}) *Row
QueryRowEx delegates to the underlying *Conn
func (*Tx) Rollback ¶
Rollback rolls back the transaction. Rollback will return ErrTxClosed if the Tx is already closed, but is otherwise safe to call multiple times. Hence, a defer tx.Rollback() is safe even if tx.Commit() will be called first in a non-error condition.
func (*Tx) RollbackEx ¶
RollbackEx is the context version of Rollback
type TxAccessMode ¶
type TxAccessMode string
type TxDeferrableMode ¶
type TxDeferrableMode string
type TxIsoLevel ¶
type TxIsoLevel string
type TxOptions ¶
type TxOptions struct { IsoLevel TxIsoLevel AccessMode TxAccessMode DeferrableMode TxDeferrableMode }
type WalMessage ¶
type WalMessage struct { // The WAL start position of this data. This // is the WAL position we need to track. WalStart uint64 // The server wal end and server time are // documented to track the end position and current // time of the server, both of which appear to be // unimplemented in pg 9.5. ServerWalEnd uint64 ServerTime uint64 // The WAL data is the raw unparsed binary WAL entry. // The contents of this are determined by the output // logical encoding plugin. WalData []byte }
The WAL message contains WAL payload entry data
func (*WalMessage) ByteLag ¶
func (w *WalMessage) ByteLag() uint64
func (*WalMessage) String ¶
func (w *WalMessage) String() string
func (*WalMessage) Time ¶
func (w *WalMessage) Time() time.Time
Source Files ¶
Directories ¶
Path | Synopsis |
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examples
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internal
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log
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log15adapter
Package log15adapter provides a logger that writes to a github.com/inconshreveable/log15.Logger log.
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Package log15adapter provides a logger that writes to a github.com/inconshreveable/log15.Logger log. |
logrusadapter
Package logrusadapter provides a logger that writes to a github.com/sirupsen/logrus.Logger log.
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Package logrusadapter provides a logger that writes to a github.com/sirupsen/logrus.Logger log. |
testingadapter
Package testingadapter provides a logger that writes to a test or benchmark log.
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Package testingadapter provides a logger that writes to a test or benchmark log. |
zapadapter
Package zapadapter provides a logger that writes to a go.uber.org/zap.Logger.
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Package zapadapter provides a logger that writes to a go.uber.org/zap.Logger. |
Package pgio is a low-level toolkit building messages in the PostgreSQL wire protocol.
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Package pgio is a low-level toolkit building messages in the PostgreSQL wire protocol. |
Package stdlib is the compatibility layer from pgx to database/sql.
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Package stdlib is the compatibility layer from pgx to database/sql. |