gitea/vendor/xorm.io/xorm/README_CN.md

xorm

English

xorm 是一个简单而强大的Go语言ORM库. 通过它可以使数据库操作非常简便。

Notice

v1.0.0 相对于 v0.8.2 有以下不兼容的变更：

• 移除了部分不符合Go语言命名的函数，如 Id, Sql，请使用 ID, SQL 替代。
• 删除了对 xorm.io/core 的依赖。大部分代码迁移到了 xorm.io/xorm/core, xorm.io/xorm/names, xorm.io/xorm/schemas 等等几个包中.
• 重命名了几个结构体，如： core.IMapper -> names.Mapper, core.ILogger -> log.Logger.

特性

• 支持 Struct 和数据库表之间的灵活映射，并支持自动同步
• 事务支持
• 同时支持原始SQL语句和ORM操作的混合执行
• 使用连写来简化调用
• 支持使用ID, In, Where, Limit, Join, Having, Table, SQL, Cols等函数和结构体等方式作为条件
• 支持级联加载Struct
• Schema支持（仅Postgres）
• 支持缓存
• 通过 xorm.io/reverse 支持根据数据库自动生成 xorm 结构体
• 支持记录版本（即乐观锁）
• 通过 xorm.io/builder 内置 SQL Builder 支持
• 上下文缓存支持
• 支持日志上下文

驱动支持

目前支持的Go数据库驱动和对应的数据库如下：

• Mysql5.* / Mysql8.* / Mariadb / Tidb

  • github.com/go-sql-driver/mysql
  • github.com/ziutek/mymysql/godrv

• Postgres / Cockroach

  • github.com/lib/pq
  • github.com/jackc/pgx

• SQLite

  • github.com/mattn/go-sqlite3
  • modernc.org/sqlite (Windows试验性支持)

• MsSql

  • github.com/denisenkom/go-mssqldb

• Oracle

  • github.com/godror/godror (试验性支持)
  • github.com/mattn/go-oci8 (试验性支持)

安装

go get xorm.io/xorm

文档

• 操作指南

• Godoc代码文档

快速开始

• 第一步创建引擎，driverName, dataSourceName 和 database/sql 接口相同

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

• 定义一个和表同步的结构体，并且自动同步结构体到数据库

type User struct {
    Id int64
    Name string
    Salt string
    Age int
    Passwd string `xorm:"varchar(200)"`
    Created time.Time `xorm:"created"`
    Updated time.Time `xorm:"updated"`
}

err := engine.Sync2(new(User))

• 创建Engine组

dataSourceNameSlice := []string{masterDataSourceName, slave1DataSourceName, slave2DataSourceName}
engineGroup, err := xorm.NewEngineGroup(driverName, dataSourceNameSlice)

masterEngine, err := xorm.NewEngine(driverName, masterDataSourceName)
slave1Engine, err := xorm.NewEngine(driverName, slave1DataSourceName)
slave2Engine, err := xorm.NewEngine(driverName, slave2DataSourceName)
engineGroup, err := xorm.NewEngineGroup(masterEngine, []*Engine{slave1Engine, slave2Engine})

所有使用 engine 都可以简单的用 engineGroup 来替换。

• Query 最原始的也支持SQL语句查询，返回的结果类型为 []map[string][]byte。QueryString 返回 []map[string]string, QueryInterface 返回 []map[string]interface{}.

results, err := engine.Query("select * from user")
results, err := engine.Where("a = 1").Query()

results, err := engine.QueryString("select * from user")
results, err := engine.Where("a = 1").QueryString()

results, err := engine.QueryInterface("select * from user")
results, err := engine.Where("a = 1").QueryInterface()

• Exec 执行一个SQL语句

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

• Insert 插入一条或者多条记录

affected, err := engine.Insert(&user)
// INSERT INTO struct () values ()

affected, err := engine.Insert(&user1, &user2)
// INSERT INTO struct1 () values ()
// INSERT INTO struct2 () values ()

affected, err := engine.Insert(&users)
// INSERT INTO struct () values (),(),()

affected, err := engine.Insert(&user1, &users)
// INSERT INTO struct1 () values ()
// INSERT INTO struct2 () values (),(),()

• Get 查询单条记录

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

has, err := engine.Where("name = ?", name).Desc("id").Get(&user)
// SELECT * FROM user WHERE name = ? ORDER BY id DESC LIMIT 1

var name string
has, err := engine.Table(&user).Where("id = ?", id).Cols("name").Get(&name)
// SELECT name FROM user WHERE id = ?

var id int64
has, err := engine.Table(&user).Where("name = ?", name).Cols("id").Get(&id)
has, err := engine.SQL("select id from user").Get(&id)
// SELECT id FROM user WHERE name = ?

var valuesMap = make(map[string]string)
has, err := engine.Table(&user).Where("id = ?", id).Get(&valuesMap)
// SELECT * FROM user WHERE id = ?

var valuesSlice = make([]interface{}, len(cols))
has, err := engine.Table(&user).Where("id = ?", id).Cols(cols...).Get(&valuesSlice)
// SELECT col1, col2, col3 FROM user WHERE id = ?

• Exist 检测记录是否存在

has, err := testEngine.Exist(new(RecordExist))
// SELECT * FROM record_exist LIMIT 1

has, err = testEngine.Exist(&RecordExist{
		Name: "test1",
	})
// SELECT * FROM record_exist WHERE name = ? LIMIT 1

has, err = testEngine.Where("name = ?", "test1").Exist(&RecordExist{})
// SELECT * FROM record_exist WHERE name = ? LIMIT 1

has, err = testEngine.SQL("select * from record_exist where name = ?", "test1").Exist()
// select * from record_exist where name = ?

has, err = testEngine.Table("record_exist").Exist()
// SELECT * FROM record_exist LIMIT 1

has, err = testEngine.Table("record_exist").Where("name = ?", "test1").Exist()
// SELECT * FROM record_exist WHERE name = ? LIMIT 1

• Find 查询多条记录，当然可以使用Join和extends来组合使用

var users []User
err := engine.Where("name = ?", name).And("age > 10").Limit(10, 0).Find(&users)
// SELECT * FROM user WHERE name = ? AND age > 10 limit 10 offset 0

type Detail struct {
    Id int64
    UserId int64 `xorm:"index"`
}

type UserDetail struct {
    User `xorm:"extends"`
    Detail `xorm:"extends"`
}

var users []UserDetail
err := engine.Table("user").Select("user.*, detail.*")
    Join("INNER", "detail", "detail.user_id = user.id").
    Where("user.name = ?", name).Limit(10, 0).
    Find(&users)
// SELECT user.*, detail.* FROM user INNER JOIN detail WHERE user.name = ? limit 10 offset 0

• Iterate 和 Rows 根据条件遍历数据库，可以有两种方式: Iterate and Rows

err := engine.Iterate(&User{Name:name}, func(idx int, bean interface{}) error {
    user := bean.(*User)
    return nil
})
// SELECT * FROM user

err := engine.BufferSize(100).Iterate(&User{Name:name}, func(idx int, bean interface{}) error {
    user := bean.(*User)
    return nil
})
// SELECT * FROM user Limit 0, 100
// SELECT * FROM user Limit 101, 100

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

• Update 更新数据，除非使用Cols,AllCols函数指明，默认只更新非空和非0的字段

affected, err := engine.ID(1).Update(&user)
// UPDATE user SET ... Where id = ?

affected, err := engine.Update(&user, &User{Name:name})
// UPDATE user SET ... Where name = ?

var ids = []int64{1, 2, 3}
affected, err := engine.In(ids).Update(&user)
// UPDATE user SET ... Where id IN (?, ?, ?)

// force update indicated columns by Cols
affected, err := engine.ID(1).Cols("age").Update(&User{Name:name, Age: 12})
// UPDATE user SET age = ?, updated=? Where id = ?

// force NOT update indicated columns by Omit
affected, err := engine.ID(1).Omit("name").Update(&User{Name:name, Age: 12})
// UPDATE user SET age = ?, updated=? Where id = ?

affected, err := engine.ID(1).AllCols().Update(&user)
// UPDATE user SET name=?,age=?,salt=?,passwd=?,updated=? Where id = ?

• Delete 删除记录，需要注意，删除必须至少有一个条件，否则会报错。要清空数据库可以用EmptyTable

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

affected, err := engine.ID(2).Delete(&user)
// DELETE FROM user Where id = ?

affected, err := engine.Table("user").Where(...).Delete()
// DELETE FROM user WHERE ...

• Count 获取记录条数

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

• Sum 求和函数

agesFloat64, err := engine.Sum(&user, "age")
// SELECT sum(age) AS total FROM user

agesInt64, err := engine.SumInt(&user, "age")
// SELECT sum(age) AS total FROM user

sumFloat64Slice, err := engine.Sums(&user, "age", "score")
// SELECT sum(age), sum(score) FROM user

sumInt64Slice, err := engine.SumsInt(&user, "age", "score")
// SELECT sum(age), sum(score) FROM user

• 条件编辑器

err := engine.Where(builder.NotIn("a", 1, 2).And(builder.In("b", "c", "d", "e"))).Find(&users)
// SELECT id, name ... FROM user WHERE a NOT IN (?, ?) AND b IN (?, ?, ?)

• 在一个Go程中多次操作数据库，但没有事务

session := engine.NewSession()
defer session.Close()

user1 := Userinfo{Username: "xiaoxiao", Departname: "dev", Alias: "lunny", Created: time.Now()}
if _, err := session.Insert(&user1); err != nil {
    return err
}

user2 := Userinfo{Username: "yyy"}
if _, err := session.Where("id = ?", 2).Update(&user2); err != nil {
    return err
}

if _, err := session.Exec("delete from userinfo where username = ?", user2.Username); err != nil {
    return err
}

return nil

• 在一个Go程中有事务

session := engine.NewSession()
defer session.Close()

// add Begin() before any action
if err := session.Begin(); err != nil {
    // if returned then will rollback automatically
    return err
}

user1 := Userinfo{Username: "xiaoxiao", Departname: "dev", Alias: "lunny", Created: time.Now()}
if _, err := session.Insert(&user1); err != nil {
    return err
}

user2 := Userinfo{Username: "yyy"}
if _, err := session.Where("id = ?", 2).Update(&user2); err != nil {
    return err
}

if _, err := session.Exec("delete from userinfo where username = ?", user2.Username); err != nil {
    return err
}

// add Commit() after all actions
return session.Commit()

• 事务的简写方法

res, err := engine.Transaction(func(session *xorm.Session) (interface{}, error) {
    user1 := Userinfo{Username: "xiaoxiao", Departname: "dev", Alias: "lunny", Created: time.Now()}
    if _, err := session.Insert(&user1); err != nil {
        return nil, err
    }

    user2 := Userinfo{Username: "yyy"}
    if _, err := session.Where("id = ?", 2).Update(&user2); err != nil {
        return nil, err
    }

    if _, err := session.Exec("delete from userinfo where username = ?", user2.Username); err != nil {
        return nil, err
    }
    return nil, nil
})

• 上下文缓存，如果启用，那么针对单个对象的查询将会被缓存到系统中，可以被下一个查询使用。

	sess := engine.NewSession()
	defer sess.Close()

	var context = xorm.NewMemoryContextCache()

	var c2 ContextGetStruct
	has, err := sess.ID(1).ContextCache(context).Get(&c2)
	assert.NoError(t, err)
	assert.True(t, has)
	assert.EqualValues(t, 1, c2.Id)
	assert.EqualValues(t, "1", c2.Name)
	sql, args := sess.LastSQL()
	assert.True(t, len(sql) > 0)
	assert.True(t, len(args) > 0)

	var c3 ContextGetStruct
	has, err = sess.ID(1).ContextCache(context).Get(&c3)
	assert.NoError(t, err)
	assert.True(t, has)
	assert.EqualValues(t, 1, c3.Id)
	assert.EqualValues(t, "1", c3.Name)
	sql, args = sess.LastSQL()
	assert.True(t, len(sql) == 0)
	assert.True(t, len(args) == 0)

贡献

如果您也想为Xorm贡献您的力量，请查看 CONTRIBUTING。您也可以加入QQ群 技术帮助和讨论。 群一：280360085 （已满） 群二：795010183

Credits

Contributors

感谢所有的贡献者. [Contribute].

Backers

感谢我们所有的 backers! 🙏 [成为 backer]

Sponsors

成为 sponsor 来支持 xorm。您的 logo 将会被显示并被链接到您的网站。 [成为 sponsor]

案例

• Gitea - github.com/go-gitea/gitea

• Gogs - github.com/gogits/gogs

• grafana - github.com/grafana/grafana

• Go语言中文网 - github.com/studygolang/studygolang

• github.com/m3ng9i/qreader

• Wego

• Docker.cn

• Xorm Adapter for Casbin - github.com/casbin/xorm-adapter

• Gowalker - github.com/Unknwon/gowalker

• Gobuild.io - github.com/shxsun/gobuild

• Sudo China - github.com/insionng/toropress

• Godaily - github.com/govc/godaily

• YouGam

• GoCMS - github.com/zzboy/GoCMS

• GoBBS - gobbs.domolo.com

• go-blog - github.com/easykoo/go-blog

更新日志

请访问 CHANGELOG.md 获得更新日志。

LICENSE

BSD License http://creativecommons.org/licenses/BSD/