数据库无关的GO语言ORM - hood

项目地址:https://github.com/eaigner/hood

这是一个极具美感的ORM库。

特性

• 链式的api
  
• 事务支持
  
• 迁移和名字空间生成
  
• 模型变量
  
• 模型时间
  
• 数据库方言接口
  
• 没有含糊的字段
  
• 干净可测试的代码

打开数据库

如果方言已经注册可以直接打开数据库

hd, err := hood.Open("postgres", "user= dbname=")

你也可以打开数据库时候指定方言

	
hd := hood.New(db, NewPostgres())

Schemas

你可以这样声明

type Person struct {
 
// Auto-incrementing int field 'id'
 Id hood.Id
 
 
// Custom primary key field 'first_name', with presence validation
 FirstName string `sql:"pk" validate:"presence"`
 
 
// string field 'last_name' with size 128, NOT NULL
 LastName string `sql:"size(128),notnull"`
 
 
// string field 'tag' with size 255, default value 'customer'
 Tag string `sql:"size(255),default('customer')"`
 
 
// You can also combine tags, default value 'orange'
 CombinedTags string `sql:"size(128),default('orange')"`
 Birthday time.Time 
// timestamp field 'birthday'
 Data []byte 
// data field 'data'
 IsAdmin bool 
// boolean field 'is_admin'
 Notes string 
// text field 'notes'
 
 
// You can alternatively define a var char as a string field by setting a size
 Nick string `sql:"size(128)"`
 
 
// Validates number range
 Balance int `validate:"range(10:20)"`
 
 
// These fields are auto updated on save
 Created hood.Created
 Updated hood.Updated
 
 
// ... and other built in types (int, uint, float...)
}
 
// Indexes are defined via the Indexed interface to avoid
// polluting the table fields.
 
func (table *Person) Indexes(indexes *hood.Indexes) {
 indexes.Add("tag_index", "tag")
// params: indexName, unique, columns...
 indexes.AddUnique("name_index", "first_name", "last_name")
}

数据迁移

你要先安装hood tool ,然后运行

go get github.com/eaigner/hood
cd $GOPATH/src/github.com/eaigner/hood
./install.sh<

例子

下面是一个使用例子

package main
 
import (
 "hood"
)
 
func main() {
 
// Open a DB connection, use New() alternatively for unregistered dialects
 hd, err := hood.Open("postgres", "user=hood dbname=hood_test sslmode=disable")
 if err != nil {
 panic(err)
 }
 
 
// Create a table
 type Fruit struct {
 Id hood.Id
 Name string `validate:"presence"`
 Color string
 }
 
 err = hd.CreateTable(&Fruit{})
 if err != nil {
 panic(err)
 }
 
 fruits := []Fruit{
 Fruit{Name: "banana", Color: "yellow"},
 Fruit{Name: "apple", Color: "red"},
 Fruit{Name: "grapefruit", Color: "yellow"},
 Fruit{Name: "grape", Color: "green"},
 Fruit{Name: "pear", Color: "yellow"},
 }
 
 
// Start a transaction
 tx := hd.Begin()
 
 ids, err := tx.SaveAll(&fruits)
 if err != nil {
 panic(err)
 }
 
 fmt.Println("inserted ids:", ids)
// [1 2 3 4 5]
 
 
// Commit changes
 err = tx.Commit()
 if err != nil {
 panic(err)
 }
 
 
// Ids are automatically updated
 if fruits[0].Id != 1 || fruits[1].Id != 2 || fruits[2].Id != 3 {
 panic("id not set")
 }
 
 
// If an id is already set, a call to save will result in an update
 fruits[0].Color = "green"
 
 ids, err = hd.SaveAll(&fruits)
 if err != nil {
 panic(err)
 }
 
 fmt.Println("updated ids:", ids)
// [1 2 3 4 5]
 
 if fruits[0].Id != 1 || fruits[1].Id != 2 || fruits[2].Id != 3 {
 panic("id not set")
 }
 
 
// Let's try to save a row that does not satisfy the required validations
 _, err = hd.Save(&Fruit{})
 if err == nil || err.Error() != "value not set" {
 panic("does not satisfy validations, should not save")
 }
 
 
// Find
 
//
 
// The markers are db agnostic, so you can always use '?'
 
// e.g. in Postgres they are replaced with 1,ドル 2,ドル ...
 var results []Fruit
 err = hd.Where("color", "=", "green").OrderBy("name").Limit(1).Find(&results)
 if err != nil {
 panic(err)
 }
 
 fmt.Println("results:", results)
// [{1 banana green}]
 
 
// Delete
 ids, err = hd.DeleteAll(&results)
 if err != nil {
 panic(err)
 }
 
 fmt.Println("deleted ids:", ids)
// [1]
 
 results = nil
 err = hd.Find(&results)
 if err != nil {
 panic(err)
 }
 
 fmt.Println("results:", results)
// [{2 apple red} {3 grapefruit yellow} {4 grape green} {5 pear yellow}]
 
 
// Drop
 hd.DropTable(&Fruit{})
}

本文来自:博客园

感谢作者:x3d

查看原文:数据库无关的GO语言ORM - hood

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