gorm源码1 目录分析

gorm目录文件如下:

主要文件是callback main scope search field dialect(.go)这几个文件

• callback.go type Callback struct包含所有CRUD的回调函数, DefaultCallback是gorm框架用的回调变量
• association.go type Association struct包含很多与关系相关的帮助函数. 如Association::Find, Association::Append等
  • 具体用法见gorm教程的"关联"部分
• dialect.go type Dialect interface包含一些数据库相关的操作, 不同的数据库(mysql, sqlite, postgress)的具体实现不同
• error.go 用var定义了一些error

  var (
    // ErrRecordNotFound returns a "record not found error". Occurs only when attempting to query the database with a struct; querying with a slice won't return this error
    ErrRecordNotFound = errors.New("record not found")
    ...
   )
  

  另外定义了type Errors []error, 且实现了Error接口,让其可以像Error一样使用.
• field.go type Field struct

  // Field model field definition
  type Field struct {
     *StructField
     IsBlank bool
     Field   reflect.Value
  }
  

• interface.go 定义了SQLCommon, sqlDb, sqlTx三个接口
• logger.go 最关键定义了type Logger struct:

  func (logger Logger) Print(values ...interface{}) {
     logger.Println(LogFormatter(values...)...)
  }
  

• main.go 主要定义了DB
• model.go 主要定义了type Model struct:

  // Model base model definition, including fields `ID`, `CreatedAt`, `UpdatedAt`, `DeletedAt`, which could be embedded in your models
  //    type User struct {
  //      gorm.Model
  //    }
  type Model struct {
       ID        uint `gorm:"primary_key"`
       CreatedAt time.Time
       UpdatedAt time.Time
       DeletedAt *time.Time `sql:"index"`
  }
  

• model_struct.go 定义了ModelStruct, StructField, Relationship三个struct, 并为Scope定义了两个成员函数(为何要在这定义). 你在实体struct中编写tag后，就会被解析到这三个类中.
• naming.go 定义了Namer函数和NamingStrategy结构体，NamingStrategy定义了数据库、表、列的命名方式(都是驼峰转下划线)

  // Namer is a function type which is given a string and return a string
  type Namer func(string) string
  
  // NamingStrategy represents naming strategies
  type NamingStrategy struct {
       DB     Namer
       Table  Namer
       Column Namer
  }
  // TheNamingStrategy is being initialized with defaultNamingStrategy
  var TheNamingStrategy = &NamingStrategy{
     DB:     defaultNamer,
     Table:  defaultNamer,
     Column: defaultNamer,
  }
  

• scope.go type Scope struct包含了当前你要操作的各种操作
• search.go 包含了搜索条件
• utils.go 放了很多工具函数