pgxiter

README

pgxiter

A cursor based iterator for pgx

Getting Started

You can use these examples to get started.

Documentation

Index

• type Cursor
  • func (r *Cursor) Close()
  • func (r *Cursor) CommandTag() pgconn.CommandTag
  • func (r *Cursor) Conn() *pgx.Conn
  • func (r *Cursor) Err() error
  • func (r *Cursor) FieldDescriptions() []pgconn.FieldDescription
  • func (r *Cursor) Next() bool
  • func (r *Cursor) RawValues() [][]byte
  • func (r *Cursor) Scan(dest ...any) error
  • func (r *Cursor) Values() ([]any, error)
• type Querier
  • func (c *Querier) Query(ctx context.Context, query string, args ...any) (pgx.Rows, error)
• type Queryable

Examples

• Querier

Types

type Cursor

type Cursor struct {
	// contains filtered or unexported fields
}

Cursor is a wrapper around pgx.Cursor.

func (*Cursor) Close

func (r *Cursor) Close()

Close implements pgx.Rows.

func (*Cursor) CommandTag

func (r *Cursor) CommandTag() pgconn.CommandTag

CommandTag implements pgx.Rows.

func (*Cursor) Conn

func (r *Cursor) Conn() *pgx.Conn

Conn implements pgx.Rows.

func (*Cursor) Err

func (r *Cursor) Err() error

Err implements pgx.Rows.

func (*Cursor) FieldDescriptions

func (r *Cursor) FieldDescriptions() []pgconn.FieldDescription

FieldDescriptions implements pgx.Rows.

func (*Cursor) Next

func (r *Cursor) Next() bool

Next implements pgx.Rows.

func (*Cursor) RawValues

func (r *Cursor) RawValues() [][]byte

RawValues implements pgx.Rows.

func (*Cursor) Scan

func (r *Cursor) Scan(dest ...any) error

Scan implements pgx.Rows.

func (*Cursor) Values

func (r *Cursor) Values() ([]any, error)

Values implements pgx.Rows.

type Querier

type Querier struct {
	// Capacity is the maximum number of rows to fetch for each iteration.
	Capacity int
	// Querier is the interface that wraps the Query method.
	Querier Queryable
}

Querier represents a PostgreSQL cursor querier.

Example

config, err := pgxpool.ParseConfig(os.Getenv("PGX_DATABASE_URL"))
if err != nil {
	panic(err)
}

conn, err := pgxpool.NewWithConfig(context.TODO(), config)
if err != nil {
	panic(err)
}
// close the pool
defer conn.Close()

querier := &pgxiter.Querier{Querier: conn}
// start the cursor
rows, err := querier.Query(context.TODO(), "SELECT * FROM user")
if err != nil {
	panic(err)
}
// close the cursor
defer rows.Close()

// User represents a user.
type User struct {
	Name     string `db:"name"`
	Password string `db:"password"`
}

for rows.Next() {
	user, err := pgx.RowToStructByName[User](rows)
	if err != nil {
		panic(err)
	}

	fmt.Println(user.Name)
}

func (*Querier) Query

func (c *Querier) Query(ctx context.Context, query string, args ...any) (pgx.Rows, error)

Query executes a query that returns rows.

type Queryable

type Queryable interface {
	// Begin starts a pseudo nested transaction.
	Begin(ctx context.Context) (pgx.Tx, error)
	// Exec executes a query that doesn't return rows.
	Exec(ctx context.Context, query string, args ...any) (pgconn.CommandTag, error)
	// Query executes a query that returns rows.
	Query(ctx context.Context, query string, args ...any) (pgx.Rows, error)
}

Queryable is the interface that wraps the Query method.