View definition

package xorm

Defined in github.com/go-xorm/xorm/.

Description

Package xorm is a simple and powerful ORM for Go.

Installation

Make sure you have installed Go 1.1+ and then:

go get github.com/go-xorm/xorm

Create Engine

Firstly, we should new an engine for a database

engine, err := xorm.NewEngine(driverName, dataSourceName)

Method NewEngine's parameters is the same as sql.Open. It depends drivers' implementation. Generally, one engine for an application is enough. You can set it as package variable.

Raw Methods

Xorm also support raw sql execution:

1. query a SQL string, the returned results is []map[string][]byte

results, err := engine.Query("select * from user")

2. execute a SQL string, the returned results

affected, err := engine.Exec("update user set .... where ...")

ORM Methods

There are 7 major ORM methods and many helpful methods to use to operate database.

1. Insert one or multipe records to database

affected, err := engine.Insert(&struct)
// INSERT INTO struct () values ()
affected, err := engine.Insert(&struct1, &struct2)
// INSERT INTO struct1 () values ()
// INSERT INTO struct2 () values ()
affected, err := engine.Insert(&sliceOfStruct)
// INSERT INTO struct () values (),(),()
affected, err := engine.Insert(&struct1, &sliceOfStruct2)
// INSERT INTO struct1 () values ()
// INSERT INTO struct2 () values (),(),()

2. Query one record from database

has, err := engine.Get(&user)
// SELECT * FROM user LIMIT 1

3. Query multiple records from database

sliceOfStructs := new(Struct)
err := engine.Find(sliceOfStructs)
// SELECT * FROM user

4. Query multiple records and record by record handle, there two methods, one is Iterate, another is Rows

err := engine.Iterate(...)
// SELECT * FROM user

rows, err := engine.Rows(...)
// SELECT * FROM user
defer rows.Close()
bean := new(Struct)
for rows.Next() {
    err = rows.Scan(bean)
}

5. Update one or more records

affected, err := engine.Id(...).Update(&user)
// UPDATE user SET ...

6. Delete one or more records, Delete MUST has conditon

affected, err := engine.Where(...).Delete(&user)
// DELETE FROM user Where ...

7. Count records

counts, err := engine.Count(&user)
// SELECT count(*) AS total FROM user

Conditions

The above 7 methods could use with condition methods chainable. Attention: the above 7 methods should be the last chainable method.

1. Id, In

engine.Id(1).Get(&user) // for single primary key
// SELECT * FROM user WHERE id = 1
engine.Id(core.PK{1, 2}).Get(&user) // for composite primary keys
// SELECT * FROM user WHERE id1 = 1 AND id2 = 2
engine.In("id", 1, 2, 3).Find(&users)
// SELECT * FROM user WHERE id IN (1, 2, 3)
engine.In("id", []int{1, 2, 3})
// SELECT * FROM user WHERE id IN (1, 2, 3)

2. Where, And, Or

engine.Where().And().Or().Find()
// SELECT * FROM user WHERE (.. AND ..) OR ...

3. OrderBy, Asc, Desc

engine.Asc().Desc().Find()
// SELECT * FROM user ORDER BY .. ASC, .. DESC
engine.OrderBy().Find()
// SELECT * FROM user ORDER BY ..

4. Limit, Top

engine.Limit().Find()
// SELECT * FROM user LIMIT .. OFFSET ..
engine.Top(5).Find()
// SELECT TOP 5 * FROM user // for mssql
// SELECT * FROM user LIMIT .. OFFSET 0 //for other databases

5. Sql, let you custom SQL

var users []User
engine.Sql("select * from user").Find(&users)

6. Cols, Omit, Distinct

var users []*User
engine.Cols("col1, col2").Find(&users)
// SELECT col1, col2 FROM user
engine.Cols("col1", "col2").Where().Update(user)
// UPDATE user set col1 = ?, col2 = ? Where ...
engine.Omit("col1").Find(&users)
// SELECT col2, col3 FROM user
engine.Omit("col1").Insert(&user)
// INSERT INTO table (non-col1) VALUES ()
engine.Distinct("col1").Find(&users)
// SELECT DISTINCT col1 FROM user

7. Join, GroupBy, Having

engine.GroupBy("name").Having("name='xlw'").Find(&users)
//SELECT * FROM user GROUP BY name HAVING name='xlw'
engine.Join("LEFT", "userdetail", "user.id=userdetail.id").Find(&users)
//SELECT * FROM user LEFT JOIN userdetail ON user.id=userdetail.id

More usage, please visit http://xorm.io/docs