pg_util

README

pg_util

PostgreSQL utilities for Go

Documentation

Index

• func BuildInsert(o InsertOpts) (sql string, args []interface{})
• func ExecAll(ctx context.Context, tx pgx.Tx, q ...string) error
• func ExtractException(err error) string
• func InTransaction(ctx context.Context, conn TxStarter, fn func(pgx.Tx) error) (err error)
• func Listen(opts ListenOpts) (err error)
• type InsertOpts
• type ListenOpts
• type TxStarter

Functions

func BuildInsert

func BuildInsert(o InsertOpts) (sql string, args []interface{})

Build and cache insert statement for all fields of data. This includes embedded struct fields.

See InsertOpts for further documentation.

func ExecAll

func ExecAll(ctx context.Context, tx pgx.Tx, q ...string) error

Execute all SQL statement strings and return on first error, if any.

func ExtractException

func ExtractException(err error) string

Try to extract an exception message, if err is *pgconn.PgError

func InTransaction

func InTransaction(
	ctx context.Context,
	conn TxStarter,
	fn func(pgx.Tx) error,
) (err error)

InTransaction runs a function inside a transaction and handles commiting and rollback on error.

Can also be used for nested pseudotransactions via savepoints.

ctx: Context to bind the query to conn: Anything, that can start a new transaction or subtransaction. fn: Function to execute on the transaction.

func Listen

func Listen(opts ListenOpts) (err error)

Listen assigns a function to listen to Postgres notifications on a channel

Types

type InsertOpts

type InsertOpts struct {
	// Table to insert into
	Table string

	// Struct that will have all its public fields written to the database.
	//
	// Use `db:"name"` to override the default name of a column.
	//
	// Tags with ",string" after the name will be converted to a string before
	// being passed to the driver. This is useful in some cases like encoding to
	// Postgres domains. This also works, if the name part of the tag is empty.
	// Examples: `db:"name,string"` `db:",string"`
	//
	// Fields with a `db:"-"` tag will be skipped
	//
	// First the fields in struct itself are scanned and then the fields in any
	// embedded structs using depth first search.
	// If duplicate column names (from the struct field name or `db` struct tag)
	// exist, the first found value will ber used.
	Data interface{}

	// Optional prefix to statement
	Prefix string

	// Optional suffix to statement
	Suffix string
}

Options for building insert statement

type ListenOpts

type ListenOpts struct {
	// Prevent identical messages from triggering the handler for up to
	// DebounceInterval. If 0, all messages trigger the handler.
	DebounceInterval time.Duration

	// URL to connect to the database on. Required.
	ConnectionURL string

	// Channel to listen on. Required.
	Channel string

	// Message handler. Required.
	OnMsg func(msg string) error

	// Optional error handler
	OnError func(err error)

	// Optional handler for database connection loss. The connection will be
	// automatically reestablished regardless, but this can be used to hook
	// extra logic on the library user's side of the application.
	OnConnectionLoss func()

	// Optional handler for reconnection after database connection loss
	OnReconnect func()

	// Optional context for cancelling listening
	Context context.Context
}

Options for calling Listen()

type TxStarter

type TxStarter interface {
	Begin(context.Context) (pgx.Tx, error)
}

Interface required to start a transaction or subtransation via savepoints