go - 如何在GORM库模型中定义引用另一个表ID的外键？

Question

我有这三种模式

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结构中创建像这样的外键。

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)
);

怎么做到呢？

Answer 1

我找到了解决方案。实际上，我在外部这样添加了外键。因此，您需要先创建或迁移表，然后添加外键。

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")
}