Transactions

Tx is returned by Begin() and BeginTx().

WARNING

Do not use BEGIN or COMMIT statements directly like DB.Exec(ctx, "BEGIN"). Because DB is a pool of connections, there's no guarantee that you will receive the same connection that the BEGIN statement was executed on. Read more.

Transactions have the same methods as DB, plus Commit() and Rollback(). Usage is similar to the standard library:

tx := db.Begin(ctx)

// Rollback will be ignored if tx has been committed later in the function
defer tx.Rollback()

tx.Exec(ctx, "DELETE FROM user_permission WHERE user_id = :id", user)
tx.Exec(ctx, "DELETE FROM user WHERE id = :id", user)

// Commit may fail, and nothing will have been committed
tx.Commit()

A Tx will maintain a single connection for its entire life cycle, releasing it only when Commit() or Rollback() is called, so always call one of them to avoid leaking connections.

Because a transaction has only one connection, it can only execute one statement at a time. If you attempt to send data to the server while it's sending you a result (from Scanner or sql.Rows), it can potentially corrupt the connection.