Simple and Powerful ORM for Go, support mysql,postgres,tidb,sqlite3,sqlite,mssql,oracle,cockroach https://xorm.io
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// Copyright 2013 - 2016 The XORM Authors. All rights reserved.
// Use of this source code is governed by a BSD
// license that can be found in the LICENSE file.
/*
Package xorm is a simple and powerful ORM for Go.
Installation
Make sure you have installed Go 1.11+ and then:
go get xorm.io/xorm
Create Engine
Firstly, we should create an engine for a database
engine, err := xorm.NewEngine(driverName, dataSourceName)
Method NewEngine's parameters are the same as sql.Open which depend drivers' implementation.
Generally, one engine for an application is enough. You can define it as a package variable.
Raw Methods
XORM supports raw SQL execution:
1. query with a SQL string, the returned results is []map[string][]byte
results, err := engine.Query("select * from user")
2. query with a SQL string, the returned results is []map[string]string
results, err := engine.QueryString("select * from user")
3. query with a SQL string, the returned results is []map[string]interface{}
results, err := engine.QueryInterface("select * from user")
4. execute with a SQL string, the returned results
affected, err := engine.Exec("update user set .... where ...")
ORM Methods
There are 8 major ORM methods and many helpful methods to use to operate database.
1. Insert one or multiple 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 or one variable from database
has, err := engine.Get(&user)
// SELECT * FROM user LIMIT 1
var id int64
has, err := engine.Table("user").Where("name = ?", name).Get(&id)
// SELECT id FROM user WHERE name = ? LIMIT 1
var id int64
var name string
has, err := engine.Table(&user).Cols("id", "name").Get(&id, &name)
// SELECT id, name FROM user LIMIT 1
3. Query multiple records from database
var sliceOfStructs []Struct
err := engine.Find(&sliceOfStructs)
// SELECT * FROM user
var mapOfStructs = make(map[int64]Struct)
err := engine.Find(&mapOfStructs)
// SELECT * FROM user
var int64s []int64
err := engine.Table("user").Cols("id").Find(&int64s)
// SELECT id FROM user
4. Query multiple records and record by record handle, there two methods, one is Iterate,
another is Rows
err := engine.Iterate(new(User), func(i int, bean interface{}) error {
// do something
})
// SELECT * FROM user
rows, err := engine.Rows(...)
// SELECT * FROM user
defer rows.Close()
bean := new(Struct)
for rows.Next() {
err = rows.Scan(bean)
}
or
rows, err := engine.Cols("name", "age").Rows(...)
// SELECT * FROM user
defer rows.Close()
for rows.Next() {
var name string
var age int
err = rows.Scan(&name, &age)
}
5. Update one or more records
affected, err := engine.ID(...).Update(&user)
// UPDATE user SET ...
6. Delete one or more records, Delete MUST has condition
affected, err := engine.Where(...).Delete(&user)
// DELETE FROM user Where ...
7. Count records
counts, err := engine.Count(&user)
// SELECT count(*) AS total FROM user
counts, err := engine.SQL("select count(*) FROM user").Count()
// select count(*) FROM user
8. Sum records
sumFloat64, err := engine.Sum(&user, "id")
// SELECT sum(id) from user
sumFloat64s, err := engine.Sums(&user, "id1", "id2")
// SELECT sum(id1), sum(id2) from user
sumInt64s, err := engine.SumsInt(&user, "id1", "id2")
// SELECT sum(id1), sum(id2) from user
Conditions
The above 8 methods could use with condition methods chainable.
Notice: the above 8 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(schemas.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}).Find(&users)
// 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
Builder
xorm could work with xorm.io/builder directly.
1. With Where
var cond = builder.Eq{"a":1, "b":2}
engine.Where(cond).Find(&users)
2. With In
var subQuery = builder.Select("name").From("group")
engine.In("group_name", subQuery).Find(&users)
3. With Join
var subQuery = builder.Select("name").From("group")
engine.Join("INNER", subQuery, "group.id = user.group_id").Find(&users)
4. With SetExprs
var subQuery = builder.Select("name").From("group")
engine.ID(1).SetExprs("name", subQuery).Update(new(User))
5. With SQL
var query = builder.Select("name").From("group")
results, err := engine.SQL(query).Find(&groups)
6. With Query
var query = builder.Select("name").From("group")
results, err := engine.Query(query)
results, err := engine.QueryString(query)
results, err := engine.QueryInterface(query)
7. With Exec
var query = builder.Insert("a, b").Into("table1").Select("b, c").From("table2")
results, err := engine.Exec(query)
More usage, please visit http://xorm.io/docs
*/
package xorm