xorm/README.md

# xorm

[中文](https://github.com/lunny/xorm/blob/master/README_CN.md)

xorm is an ORM for Go. It makes dabatabse operating simple. 

It's not entirely ready for product use yet, but it's getting there.

## Drivers Support

Drivers for Go's sql package which currently support database/sql includes:

* Mysql: [github.com/Go-SQL-Driver/MySQL](https://github.com/Go-SQL-Driver/MySQL)

* SQLite: [github.com/mattn/go-sqlite3](https://github.com/mattn/go-sqlite3)

## Changelog

* **v0.1.2** : Insert function now supports both struct and slice pointer parameters, batch inserting and auto transaction
* **v0.1.1** : Add Id, In functions and improved README
* **v0.1.0** : Inital release.

## Features

* Struct<->Table Mapping Supports, both name mapping and filed tags mapping

* Database Transaction Support

* Both ORM and SQL Operation Support

* Simply usage

* Support Id, In, Where, Limit, Join, Having functions and sturct as query conditions

## Installing xorm

	go get github.com/lunny/xorm

## Quick Start

1.Create a database engine just like sql.Open, commonly you just need create once.

```Go
import (
	_ "github.com/Go-SQL-Driver/MySQL"
	"github.com/lunny/xorm"
)
engine := xorm.Create("mysql", "root:123@/test?charset=utf8")
```

or

```Go
import (
	_ "github.com/mattn/go-sqlite3"
	"github.com/lunny/xorm"
)
engine = xorm.Create("sqlite3", "./test.db")
```

1.1.If you want to show all generated SQL

```Go
engine.ShowSQL = true
```

2.Define a struct

```Go
type User struct {
	Id int
    Name string
    Age int    `xorm:"-"`
}
```

2.1.More mapping rules, please see [Mapping Rules](#mapping)

3.When you set up your program, you can use CreateTables to create database tables.

```Go
err := engine.CreateTables(&User{})
// or err := engine.Map(&User{}, &Article{})
// err = engine.CreateAll()
```

4.then, insert an struct to table

```Go
id, err := engine.Insert(&User{Name:"lunny"})
```

or if you want to update records

```Go
user := User{Name:"xlw"}
rows, err := engine.Update(&user, &User{Id:1})
// or rows, err := engine.Where("id = ?", 1).Update(&user)
// or rows, err := engine.Id(1).Update(&user)
```

5.Fetch a single object by user

```Go
var user = User{Id:27}
err := engine.Get(&user)
// or err := engine.Id(27).Get(&user)

var user = User{Name:"xlw"}
err := engine.Get(&user)
```
	
6.Fetch multipe objects, use Find：

```Go
var everyone []Userinfo
err := engine.Find(&everyone)
```

6.1 also you can use Where, Limit

```Go
var allusers []Userinfo
err := engine.Where("id > ?", "3").Limit(10,20).Find(&allusers) //Get id>3 limit 10 offset 20
```

6.2 or you can use a struct query

```Go
var tenusers []Userinfo
err := engine.Limit(10).Find(&tenusers, &Userinfo{Name:"xlw"}) //Get All Name="xlw" limit 10 offset 0
```

6.3 or In function

```Go
var tenusers []Userinfo
err := engine.In("id", 1, 3, 5).Find(&tenusers) //Get All id in (1, 3, 5)
```

7.Delete

```Go
err := engine.Delete(&User{Id:1})
// or err := engine.Id(1).Delete(&User{})
```

8.Count

```Go
total, err := engine.Count(&User{Name:"xlw"})
```


##Execute SQL

Of course, SQL execution is also provided.

1.if select then use Query

```Go
sql := "select * from userinfo"
results, err := engine.Query(sql)
```

2.if insert, update or delete then use Exec

```Go
sql = "update userinfo set username=? where id=?"
res, err := engine.Exec(sql, "xiaolun", 1) 
```


##Advanced Usage

for deep usage, you should create a session, this func will create a database connection immediatelly

```Go
session, err := engine.MakeSession()
defer session.Close()
if err != nil {
    return
}
```

1.Fetch a single object by where

```Go
var user Userinfo
session.Where("id=?", 27).Get(&user)

var user2 Userinfo
session.Where("name = ?", "john").Get(&user3) // more complex query

var user3 Userinfo
session.Where("name = ? and age < ?", "john", 88).Get(&user4) // even more complex
```

2.Fetch multiple objects

```Go
var allusers []Userinfo
err := session.Where("id > ?", "3").Limit(10,20).Find(&allusers) //Get id>3 limit 10 offset 20

var tenusers []Userinfo
err := session.Limit(10).Find(&tenusers, &Userinfo{Name:"xlw"}) //Get All Name="xlw" limit 10  if omit offset the default is 0

var everyone []Userinfo
err := session.Find(&everyone)
```
	
3.Transaction

```Go
// add Begin() before any action
session.Begin()	
user1 := Userinfo{Username: "xiaoxiao", Departname: "dev", Alias: "lunny", Created: time.Now()}
_, err = session.Insert(&user1)
if err != nil {
	session.Rollback()
	return
}
user2 := Userinfo{Username: "yyy"}
_, err = session.Where("id = ?", 2).Update(&user2)
if err != nil {
	session.Rollback()
	return
}

_, err = session.Delete(&user2)
if err != nil {
	session.Rollback()
	return
}

// add Commit() after all actions
err = session.Commit()
if err != nil {
	return
}
```

4.Mixed Transaction

```Go
// add Begin() before any action
session.Begin()	
user1 := Userinfo{Username: "xiaoxiao", Departname: "dev", Alias: "lunny", Created: time.Now()}
_, err = session.Insert(&user1)
if err != nil {
	session.Rollback()
	return
}
user2 := Userinfo{Username: "yyy"}
_, err = session.Where("id = ?", 2).Update(&user2)
if err != nil {
	session.Rollback()
	return
}

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

// add Commit() after all actions
err = session.Commit()
if err != nil {
	return
}
```

##Mapping Rules

<a name="mapping" id="mapping"></a>
1.Struct and struct's fields name should be Pascal style, and the table and column's name default is SQL style.

For example: 

The struct's Name 'UserInfo' will turn into the table name 'user_info', the same as the keyname. If the keyname is 'UserName' will turn into the select colum 'user_name'

2.If You want change the mapping rules, you have two methods. One is to implement your own Map struct interface according IMapper, you can find the interface in mapper.go and set it to engine.Mapper

Another is use field tag, field tag support the below keywords which split with space:

<table>
    <tr>
        <td>name</td><td>column name</td>
    </tr>
    <tr>
        <td>pk</td><td>the field is a primary key</td>
    </tr>
    <tr>
        <td>int(11)/varchar(50)</td><td>column type</td>
    </tr>
    <tr>
        <td>autoincr</td><td>auto incrment</td>
    </tr>
    <tr>
        <td>[not ]null</td><td>if column can be null value</td>
    </tr>
    <tr>
        <td>unique</td><td>unique</td>
    </tr>
    <tr>
        <td>-</td><td>this field is not map as a table column</td>
    </tr>
</table>

For Example

```Go
type Userinfo struct {
	Uid        int `xorm:"id pk not null autoincr"`
	Username   string
	Departname string
	Alias      string `xorm:"-"`
	Created    time.Time
}
```


##Documents

Please visit [GoWalker](http://gowalker.org/github.com/lunny/xorm)


##FAQ

1.How the xorm tag use both with json?
  
  Use space.

```Go
type User struct {
    Name string `json:"name" xorm:"name"`
}
```

## LICENSE

 BSD License
 [http://creativecommons.org/licenses/BSD/](http://creativecommons.org/licenses/BSD/)