sqalx

sqalx (pronounced 'scale-x') is a library built on top of sqlx that allows to seamlessly create nested transactions and to avoid thinking about whether or not a function is called within a transaction. With sqalx you can easily create reusable and composable functions that can be called within or out of transactions and that can create transactions themselves.

Getting started

$ go get github.com/heetch/sqalx

Import sqlax

import "github.com/heetch/sqalx"

Usage

package main

import (
	"log"

	"github.com/heetch/sqalx"
	"github.com/jmoiron/sqlx"
	_ "github.com/lib/pq"
)

func main() {
	// Connect to PostgreSQL with sqlx.
	db, err := sqlx.Connect("postgres", "user=foo dbname=bar sslmode=disable")
	if err != nil {
		log.Fatal(err)
	}

	defer db.Close()

	// Pass the db to sqalx.
	// It returns a sqalx.Node. A Node is a wrapper around sqlx.DB or sqlx.Tx.
	node, err := sqalx.New(db)
	if err != nil {
		log.Fatal(err)
	}

	err = createUser(node)
	if err != nil {
		log.Fatal(err)
	}
}

func createUser(node sqalx.Node) error {
	// Exec a query
	_, _ = node.Exec("INSERT INTO ....") // you can use a node as if it were a *sqlx.DB or a *sqlx.Tx

	// Let's create a transaction.
	// A transaction is also a sqalx.Node.
	tx, err := node.Beginx()
	if err != nil {
		return err
	}
	defer tx.Rollback()

	_, _ = tx.Exec("UPDATE ...")

	// Now we call another function and pass it the transaction.
	err = updateGroups(tx)
	if err != nil {
		return nil
	}

	return tx.Commit()
}

func updateGroups(node sqlax.Node) error {
	// Notice we are creating a new transaction.
	// This would normally cause a dead lock without sqalx.
	tx, err := node.Beginx()
	if err != nil {
		return err
	}
	defer tx.Rollback()

	_, _ = tx.Exec("INSERT ...")
	_, _ = tx.Exec("UPDATE ...")
	_, _ = tx.Exec("DELETE ...")

	return tx.Commit()
}

PostgreSQL Savepoints

When using the PostgreSQL driver, an option can be passed to New to enable the use of PostgreSQL Savepoints for nested transactions.

node, err := sqalx.New(db, sqalx.SavePoint(true))

Issue

Please open an issue if you encounter any problem.

License

The library is released under the MIT license. See LICENSE file.