Package txdb is a single transaction based database sql driver. When the connection is opened, it starts a transaction and all operations performed on this sql.DB will be within that transaction. If concurrent actions are performed, the lock is acquired and connection is always released the statements and rows are not holding the connection.
Why is it useful. A very basic use case would be if you want to make functional tests you can prepare a test database and within each test you do not have to reload a database. All tests are isolated within transaction and though, performs fast. And you do not have to interface your sql.DB reference in your code, txdb is like a standard sql.Driver.
This driver supports any sql.Driver connection to be opened. You can register txdb for different sql drivers and have it under different driver names. Under the hood whenever a txdb driver is opened, it attempts to open a real connection and starts transaction. When close is called, it rollbacks transaction leaving your prepared test database in the same state as before.
Given, you have a mysql database called txdb_test and a table users with a username column.
package main
import (
"database/sql"
"log"
"github.com/DATA-DOG/go-txdb"
_ "github.com/go-sql-driver/mysql"
)
func init() {
// we register an sql driver named "txdb"
txdb.Register("txdb", "mysql", "root@/txdb_test")
}
func main() {
// dsn serves as an unique identifier for connection pool
db, err := sql.Open("txdb", "identifier")
if err != nil {
log.Fatal(err)
}
defer db.Close()
if _, err := db.Exec(`INSERT INTO users(username) VALUES("gopher")`); err != nil {
log.Fatal(err)
}
}You can also use sql.OpenDB (added in Go 1.10) rather than registering a txdb driver instance, if you prefer:
package main
import (
"database/sql"
"log"
"github.com/DATA-DOG/go-txdb"
_ "github.com/go-sql-driver/mysql"
)
func main() {
db := sql.OpenDB(txdb.New("mysql", "root@/txdb_test"))
defer db.Close()
if _, err := db.Exec(`INSERT INTO users(username) VALUES("gopher")`); err != nil {
log.Fatal(err)
}
}Every time you will run this application, it will remain in the same state as before.
Usage is mainly intended for testing purposes. Tests require database access, support using postgres and mysql databases. The easiest way to do this is by using testcontainers, which is enabled by setting the respective database DSN values to AUTO. Example:
MYSQL_DSN=AUTO PSQL_DSN=AUTO go test ./...If you wish to use a running local database instance, you can also provide the DSN directly, and it will be used:
MYSQL_DSN=root:pass@/ PSQL_DSN=postgres://postgres:pass@localhost/ go test ./...To run tests only against MySQL or PostgreSQL, you may provide only the respective DSN values; any unset DSN is skipped for tests.
See godoc for general API details. See .travis.yml for supported go versions.
Feel free to open a pull request. Note, if you wish to contribute an extension to public (exported methods or types) - please open an issue before to discuss whether these changes can be accepted. All backward incompatible changes are and will be treated cautiously.
The public API is locked since it is an sql.Driver and will not change.
txdb is licensed under the three clause BSD license