Mainflux.mainflux/vendor/github.com/jackc/pgx/v5

pgx - PostgreSQL Driver and Toolkit

pgx is a pure Go driver and toolkit for PostgreSQL.

The pgx driver is a low-level, high performance interface that exposes PostgreSQL-specific features such as LISTEN / NOTIFY and COPY. It also includes an adapter for the standard database/sql interface.

The toolkit component is a related set of packages that implement PostgreSQL functionality such as parsing the wire protocol and type mapping between PostgreSQL and Go. These underlying packages can be used to implement alternative drivers, proxies, load balancers, logical replication clients, etc.

Example Usage

package main

import (
	"context"
	"fmt"
	"os"

	"github.com/jackc/pgx/v5"
)

func main() {
	// urlExample := "postgres://username:password@localhost:5432/database_name"
	conn, err := pgx.Connect(context.Background(), os.Getenv("DATABASE_URL"))
	if err != nil {
		fmt.Fprintf(os.Stderr, "Unable to connect to database: %v\n", err)
		os.Exit(1)
	}
	defer conn.Close(context.Background())

	var name string
	var weight int64
	err = conn.QueryRow(context.Background(), "select name, weight from widgets where id=$1", 42).Scan(&name, &weight)
	if err != nil {
		fmt.Fprintf(os.Stderr, "QueryRow failed: %v\n", err)
		os.Exit(1)
	}

	fmt.Println(name, weight)
}

See the getting started guide for more information.

Features

• Support for approximately 70 different PostgreSQL types
• Automatic statement preparation and caching
• Batch queries
• Single-round trip query mode
• Full TLS connection control
• Binary format support for custom types (allows for much quicker encoding/decoding)
• COPY protocol support for faster bulk data loads
• Tracing and logging support
• Connection pool with after-connect hook for arbitrary connection setup
• LISTEN / NOTIFY
• Conversion of PostgreSQL arrays to Go slice mappings for integers, floats, and strings
• hstore support
• json and jsonb support
• Maps inet and cidr PostgreSQL types to netip.Addr and netip.Prefix
• Large object support
• NULL mapping to pointer to pointer
• Supports database/sql.Scanner and database/sql/driver.Valuer interfaces for custom types
• Notice response handling
• Simulated nested transactions with savepoints

Choosing Between the pgx and database/sql Interfaces

The pgx interface is faster. Many PostgreSQL specific features such as LISTEN / NOTIFY and COPY are not available through the database/sql interface.

The pgx interface is recommended when:

1. The application only targets PostgreSQL.
2. No other libraries that require database/sql are in use.

It is also possible to use the database/sql interface and convert a connection to the lower-level pgx interface as needed.

Testing

See CONTRIBUTING.md for setup instructions.

Supported Go and PostgreSQL Versions

pgx supports the same versions of Go and PostgreSQL that are supported by their respective teams. For Go that is the two most recent major releases and for PostgreSQL the major releases in the last 5 years. This means pgx supports Go 1.19 and higher and PostgreSQL 11 and higher. pgx also is tested against the latest version of CockroachDB.

Version Policy

pgx follows semantic versioning for the documented public API on stable releases. v5 is the latest stable major version.

PGX Family Libraries

github.com/jackc/pglogrepl

pglogrepl provides functionality to act as a client for PostgreSQL logical replication.

github.com/jackc/pgmock

pgmock offers the ability to create a server that mocks the PostgreSQL wire protocol. This is used internally to test pgx by purposely inducing unusual errors. pgproto3 and pgmock together provide most of the foundational tooling required to implement a PostgreSQL proxy or MitM (such as for a custom connection pooler).

github.com/jackc/tern

tern is a stand-alone SQL migration system.

github.com/jackc/pgerrcode

pgerrcode contains constants for the PostgreSQL error codes.

Adapters for 3rd Party Types

• github.com/jackc/pgx-gofrs-uuid
• github.com/jackc/pgx-shopspring-decimal
• github.com/vgarvardt/pgx-google-uuid

Adapters for 3rd Party Tracers

• https://github.com/jackhopner/pgx-xray-tracer

Adapters for 3rd Party Loggers

These adapters can be used with the tracelog package.

• github.com/jackc/pgx-go-kit-log
• github.com/jackc/pgx-log15
• github.com/jackc/pgx-logrus
• github.com/jackc/pgx-zap
• github.com/jackc/pgx-zerolog

3rd Party Libraries with PGX Support

github.com/georgysavva/scany

Library for scanning data from a database into Go structs and more.

https://github.com/otan/gopgkrb5

Adds GSSAPI / Kerberos authentication support.

github.com/wcamarao/pmx

Explicit data mapping and scanning library for Go structs and slices.

github.com/stephenafamo/scan

Type safe and flexible package for scanning database data into Go types. Supports, structs, maps, slices and custom mapping functions.

https://github.com/z0ne-dev/mgx

Code first migration library for native pgx (no database/sql abstraction).