如何在引用另一个 table id 的 GORM 库模型中定义外键?

How to define foreign key in GORM library model referencing to another table id?

我有这三个模型

type Store struct {
    Id int `gorm: "type:int;primary_key;AUTO_INCREMENT;NOT NULL;UNIQUE"`
    Store_Id string `gorm:"type:varchar(190)";"NOT NULL";"UNIQUE"`
}

type File struct {
    Id int `gorm: "type:int;primary_key;AUTO_INCREMENT;NOT NULL;UNIQUE"`
    Organization_Id string `gorm:"type:varchar(190)";"NOT NULL"`
    File_Id string `gorm:"type:varchar(190)";"NOT NULL";"UNIQUE"`
}

type File_Store_Linker struct {
    Id int `gorm: "type:int;primary_key;AUTO_INCREMENT;NOT NULL"`
    File_Id string `gorm:"type:varchar(190)";"NOT NULL"`
    Store_Id string `gorm:"type:varchar(190)";"NOT NULL"`
    File_Type string `gorm:"type:varchar(50)";"NOT NULL"`
}

我想在 File_Storage_Linker 结构中创建这样的外键。

create table file_store_linker (
id INT NOT NULL AUTO_INCREMENT,
file_id VARCHAR(190) NOT NULL,
store_id VARCHAR(190) NOT NULL,
file_type VARCHAR(50) NOT NULL,
PRIMARY KEY (id),
FOREIGN KEY (file_id)
REFERENCES file (file_id),
FOREIGN KEY (store_id)
REFERENCES storage (store_id)
);

如何做到?

我找到了解决方法。实际上我是这样在外部添加外键的。所以你需要先创建或迁移表,然后再添加外键。

type Store struct {
    Id int `gorm: "type:int;primary_key;AUTO_INCREMENT;NOT NULL;UNIQUE"`
    Store_Id string `gorm:"type:varchar(190)";"NOT NULL";"UNIQUE"`
}

type File struct {
    Id int `gorm: "type:int;primary_key;AUTO_INCREMENT;NOT NULL;UNIQUE"`
    Organization_Id string `gorm:"type:varchar(190)";"NOT NULL"`
    File_Id string `gorm:"type:varchar(190)";"NOT NULL";"UNIQUE"`
}

type File_Store_Linker struct {
    Id int `gorm: "type:int;primary_key;AUTO_INCREMENT;NOT NULL"`
    File_Id string `gorm:"type:varchar(190)";"NOT NULL"`
    Store_Id string `gorm:"type:varchar(190)";"NOT NULL"`
    File_Type string `gorm:"type:varchar(50)";"NOT NULL"`
}

func AddForeignKeys(gormDb *gorm.DB) {
     gormDb.Model(&File_Store_Linker{}).AddForeignKey("file_id","file(file_id)", 
    "RESTRICT","RESTRICT")
 gormDb.Model(&File_Store_Linker{}).AddForeignKey("store_id","store(store_id)"," 
     RESTRICT","RESTRICT")
}