# Using Go and pgx

> [!NOTE]
> `pgx/v5` is supported starting from v1.18.0.

pgx is a pure Go driver and toolkit for PostgreSQL. It's become the default
PostgreSQL package for many Gophers since lib/pq was put into maintenance mode.

## Getting started

To start generating code that uses pgx, set the `sql_package` field in
your `sqlc.yaml` configuration file. Valid options are `pgx/v4` or
`pgx/v5`

```yaml
version: "2"
sql:
  - engine: "postgresql"
    queries: "query.sql"
    schema: "query.sql"
    gen:
      go:
        package: "db"
        sql_package: "pgx/v5"
        out: "db"
```

If you don't have an existing sqlc project on hand, create a directory with the
configuration file above and the following `query.sql` file.

```sql
CREATE TABLE authors (
  id   BIGSERIAL PRIMARY KEY,
  name text      NOT NULL,
  bio  text
);

-- name: GetAuthor :one
SELECT * FROM authors
WHERE id = $1 LIMIT 1;

-- name: ListAuthors :many
SELECT * FROM authors
ORDER BY name;

-- name: CreateAuthor :one
INSERT INTO authors (
  name, bio
) VALUES (
  $1, $2
)
RETURNING *;

-- name: DeleteAuthor :exec
DELETE FROM authors
WHERE id = $1;
```

Generating the code will now give you pgx-compatible database access methods.

```bash
sqlc generate
```

## Generated code walkthrough

The generated code is very similar to the code generated when using
`lib/pq`. However, instead of using `database/sql`, the code uses
pgx types directly.

```go
package main

import (
	"context"
	"fmt"
	"os"

	"github.com/jackc/pgx/v5"

	"example.com/sqlc-tutorial/db"
)

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())

	q := db.New(conn)

	author, err := q.GetAuthor(context.Background(), 1)
	if err != nil {
		fmt.Fprintf(os.Stderr, "GetAuthor failed: %v\n", err)
		os.Exit(1)
	}

	fmt.Println(author.Name)
}
```

> [!NOTE]
> For production applications, consider using pgxpool for connection pooling:
>
> ```go
> import (
>     "github.com/jackc/pgx/v5/pgxpool"
>     "example.com/sqlc-tutorial/db"
> )
>
> func main() {
>     pool, err := pgxpool.New(context.Background(), os.Getenv("DATABASE_URL"))
>     if err != nil {
>         fmt.Fprintf(os.Stderr, "Unable to create connection pool: %v\n", err)
>         os.Exit(1)
>     }
>     defer pool.Close()
>
>     q := db.New(pool)
>     // Use q the same way as with single connections
> }
> ```