forked from mirror/gorm
234 lines
7.6 KiB
Markdown
234 lines
7.6 KiB
Markdown
# GORM
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Yet Another ORM library for Go, aims for developer friendly
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## Overview
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* CURD
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* Chainable API
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* Before/After Create/Save/Update/Delete Callbacks
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* Order/Select/Limit/Offset Support
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* Automatically CreatedAt, UpdatedAt
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* Update, Updates Like Rails's update_attribute, update_attributes
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* Dynamically set table name when search, update, delete...
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* Create table from struct
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* Prevent SQL Injection
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* Goroutines friendly
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* Database Pool
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## Basic Usage
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```go
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db, _ = Open("postgres", "user=gorm dbname=gorm sslmode=disable")
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type User struct {
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Id int64
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Age int64
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Birthday time.Time
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Name string
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CreatedAt time.Time
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UpdatedAt time.Time
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}
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// Set database pool
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db.SetPool(10)
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// Create
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user = User{Name: "jinzhu", Age: 18, Birthday: time.Now()}
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db.Save(&user)
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// Update
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user.Name = "jinzhu 2"
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db.Save(&user)
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// Delete
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db.Delete(&user)
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// Get First matched record
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db.Where("name = ?", "jinzhu").First(&user)
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// Get All matched records
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db.Where("name = ?", "jinzhu").Find(&users)
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// Advanced Where Usage
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db.Where("name <> ?", "jinzhu").Find(&users)
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//// users -> select * from users name <> 'jinzhu';
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db.Where("name = ? and age >= ?", "jinzhu", "22").Find(&users)
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//// users -> select * from users name = 'jinzhu' and age >= 22;
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db.Where("name in (?)", []string["jinzhu", "jinzhu 2"]).Find(&users)
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//// users -> select * from users name in ('jinzhu', 'jinzhu 2');
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db.Where("name LIKE ?", "%jin%").Find(&users)
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//// users -> select * from users name LIKE "%jinzhu%";
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db.Where("birthday < ?", time.Now()).Find(&users)
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// Inline search condition
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db.First(&user, 23)
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//// user -> select * from users where id = 23 limit 1;
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db.First(&user, "name = ?", "jinzhu")
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//// user -> select * from users where name = "jinzhu" limit 1;
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db.Find(&users, "name = ?", "jinzhu")
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//// users -> select * from users where name = "jinzhu";
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db.Find(&users, "name <> ? and age > ?", "jinzhu", 20)
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//// users -> select * from users where name <> "jinzhu" and age > 20;
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// Select
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db.Select("name").Find(&users)
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//// users -> select name from users;
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// Order
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db.Order("age desc, name").Find(&users)
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//// users -> select * from users order by age desc, name;
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db.Order("age desc").Order("name").Find(&users)
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//// users -> select * from users order by age desc, name;
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// ReOrder
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db.Order("age desc").Find(&users1).Order("age", true).Find(&users2)
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//// users1 -> select * from users order by age desc;
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//// users2 -> select * from users order by age;
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// Limit
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db.Limit(3).Find(&users)
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//// users -> select * from users limit 3;
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db.Limit(10).Find(&users1).Limit(20).Find(&users2).Limit(-1).Find(&users3)
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//// users1 -> select * from users limit 10;
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//// users2 -> select * from users limit 20;
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//// users3 -> select * from users;
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// Offset
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//// select * from users offset 3;
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db.Offset(3).Find(&users)
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db.Offset(10).Find(&users1).Offset(20).Find(&users2).Offset(-1).Find(&users3)
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//// user1 -> select * from users offset 10;
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//// user2 -> select * from users offset 20;
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//// user3 -> select * from users;
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// Or
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db.Where("role = ?", "admin").Or("role = ?", "super_admin").Find(&users)
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//// users -> select * from users where role = 'admin' or role = 'super_admin';
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// Count
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db.Where("name = ?", "jinzhu").Or("name = ?", "jinzhu 2").Find(&users).Count(&count)
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//// users -> select * from users where name = 'jinzhu' or name = 'jinzhu 2';
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//// count -> select count(*) from users where name = 'jinzhu' or name = 'jinzhu 2';
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db.Model(&User{}).Where("name = ?", "jinzhu").Count(&count)
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// CreatedAt (auto insert current time on create)
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If your struct has field CreatedAt,
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it will be filled with the current time when insert into database
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// UpdatedAt (auto update the time on save)
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If your struct has field UpdatedAt,
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it will be filled with the current time when update it
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// Callbacks
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Below callbacks are defined now:
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`BeforeCreate`, `BeforeUpdate`, `BeforeSave`, `AfterCreate`, `AfterUpdate`, `AfterSave`
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`BeforeDelete`, `AfterDelete`
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Callbacks is a function defined to a model, if the function return error, will prevent the database operations.
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func (u *User) BeforeUpdate() (err error) {
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if u.readonly() {
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err = errors.New("Read Only User")
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}
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return
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}
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// Pluck (get users's age as map)
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var ages []int64
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db.Find(&users).Pluck("age", &ages)
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//// ages -> select age from users;
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var names []string
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db.Model(&User{}).Pluck("name", &names)
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//// names -> select name from users;
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// Query Chains
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db.Where("name <> ?", "jinzhu").Where("age >= ? and role <> ?", 20, "admin").Find(&users)
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//// users -> select * from users where name <> 'jinzhu' andd age >= 20 and role <> 'admin';
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// Create Table with struct
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db.CreateTable(&User{})
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// Specify Table Name
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db.Table("deleted_users").CreateTable(&User{})
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db.Table("users").Pluck("age", &ages)
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//// ages -> select age from users;
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var deleted_users []User
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db.Table("deleted_users").Find(&deleted_users)
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//// deleted_users -> select * from deleted_users;
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db.Table("deleted_users").Find(&deleted_user)
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//// deleted_user -> select * from deleted_users limit 1;
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// Update
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db.Table("users").Where(10).Update("name", "hello")
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//// update users set name='hello' where id = 10;
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db.Table("users").Update("name", "hello")
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//// update users set name='hello';
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// Updates
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db.Table("users").Where(10).Updates(map[string]interface{}{"name": "hello", "age": 18})
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//// update users set name='hello', age=18 where id = 10;
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db.Table("users").Updates(map[string]interface{}{"name": "hello", "age": 18})
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//// update users set name='hello', age=18;
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// Run Raw SQL
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db.Exec("drop table users;")
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// Error Handling
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query := db.Where("name = ?", "jinzhu").First(&user)
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query := db.First(&user).Limit(10).Find(&users)
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//// query.Error -> the last error happened
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//// query.Errors -> all errors happened
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//// If an error happened, gorm will stop do insert, update, delete operations
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```
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## Advanced Usage With Query Chain
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```go
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// Already excited about the basic usage? Let's see some magic!
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db.First(&first_article).Count(&total_count).Limit(10).Find(&first_page_articles).Offset(10).Find(&second_page_articles)
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//// first_article -> select * from articles limit 1
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//// total_count -> select count(*) from articles
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//// first_page_articles -> select * from articles limit 10
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//// second_page_articles -> select * from articles limit 10 offset 10
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db.Where("created_at > ?", "2013/10/10").Find(&cancelled_orders, "state = ?", "cancelled").Find(&shipped_orders, "state = ?", "shipped")
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//// cancelled_orders -> select * from orders where created_at > '2013/10/10' and state = 'cancelled'
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//// shipped_orders -> select * from orders where created_at > '2013/10/10' and state = 'shipped'
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db.Model(&Order{}).Where("amount > ?", 10000).Pluck("user_id", &paid_user_ids)
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//// paid_user_ids -> select user_id from orders where amount > 10000
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db.Where("user_id = ?", paid_user_ids).Find(&:paid_users)
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//// paid_users -> select * from users where user_id in (10, 20, 99)
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db.Where("product_name = ?", "fancy_product").Find(&orders).Find(&shopping_cart)
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//// orders -> select * from orders where product_name = 'fancy_product'
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//// shopping_cart -> select * from carts where product_name = 'fancy_product'
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// Do you noticed the search table is different for above query, yay
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db.Where("mail_type = ?", "TEXT").Find(&users1).Table("deleted_users").First(&user2)
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//// users1 -> select * from users where mail_type = 'TEXT';
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//// users2 -> select * from deleted_users where mail_type = 'TEXT';
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// Open your mind, add more cool examples
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```
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## TODO
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* Soft Delete
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* Query with map or struct
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* FindOrInitialize / FindOrCreate
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* SQL Log
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* Auto Migration
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* Index, Unique, Valiations
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* SQL Query with goroutines
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* Only tested with postgres, confirm works with other database adaptors
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# Author
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**Jinzhu**
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* <http://github.com/jinzhu>
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* <wosmvp@gmail.com>
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* <http://twitter.com/zhangjinzhu>
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