XORM Manual

Create ORM Engine

When using xorm, you can create multiple orm engines, an engine means a databse. So you can：

import (
    _ "github.com/go-sql-driver/mysql"
    "github.com/go-xorm/xorm"
)

var engine *xorm.Engine

func main() {
    var err error
    engine, err = xorm.NewEngine("mysql", "root:123@/test?charset=utf8")
}

or

import (
    _ "github.com/mattn/go-sqlite3"
    "github.com/go-xorm/xorm"
)

var engine *xorm.Engine

func main() {
    var err error
    engine, err = xorm.NewEngine("sqlite3", "./test.db")
}

You can create many engines for different databases.Generally, you just need create only one engine. Engine supports run on go routines.

When you want to manually close then engine, call engine.Close. Generally, we don't need to do this, because engine will be closed automatically when application exit.

xorm supports four drivers now:

• Mysql: github.com/Go-SQL-Driver/MySQL

• MyMysql: github.com/ziutek/mymysql

• SQLite: github.com/mattn/go-sqlite3

• Postgres: github.com/lib/pq

• MsSql: github.com/lunny/godbc

NewEngine's parameters are the same as sql.Open. So you should read the drivers' document for parameters' usage.

After engine created, you can do some settings.

1.Logs

• engine.ShowSQL = true, Show SQL statement on standard output;
• engine.ShowDebug = true, Show debug infomation on standard output;
• engine.ShowError = true, Show error infomation on standard output;
• engine.ShowWarn = true, Show warnning information on standard output;

2.If want to record infomation with another method: use engine.Logger as io.Writer:

f, err := os.Create("sql.log")
    if err != nil {
        println(err.Error())
        return
    }
engine.Logger = xorm.NewSimpleLogger(f)

3.Engine provide DB connection pool settings.

• Use engine.SetMaxIdleConns() to set idle connections.
• Use engine.SetMaxOpenConns() to set Max connections. This methods support only Go 1.2+.