英文:
How can I perform nested deletes gorm Golang?
问题
我有一个名为Customers的表，其中包含Cars，而Cars又有Services。
当我删除Car时，我也希望从数据库中删除Services。
当我删除Customer时，我希望能够删除Customer、它的Cars和它的Services。
我尝试了以下代码来删除Car及其相关的Services，但它只删除了数据库中的Car，如何同时删除Cars和它的Services呢？
type Customer struct {gorm.ModelFirstName stringLastName stringPhone string `gorm:"type:varchar(100);unique_index"`Cars []Car `gorm:"constraint:OnDelete:CASCADE;"`}type Car struct {gorm.ModelMake stringModelo stringColor stringVinNumber string `gorm:"type:varchar(100);unique_index"`Services []*Service `gorm:"constraint:OnDelete:CASCADE;"`CustomerId int}type Service struct {gorm.ModelComment stringMiles stringCarId int}// 删除Customer的端点func deleteCustomer(w http.ResponseWriter, r *http.Request) {params := mux.Vars(r)setupResponse(&w, r)if (*r).Method == "OPTIONS" {return}var customer Customerdb.First(&customer, params["id"])db.Unscoped().Delete(&customer)json.NewEncoder(w).Encode(&customer)}// 删除Car的端点func deleteCar(w http.ResponseWriter, r *http.Request) {setupResponse(&w, r)if (*r).Method == "OPTIONS" {return}params := mux.Vars(r)var car Cardb.First(&car, params["id"])db.Select("Services").Unscoped().Delete(&car)json.NewEncoder(w).Encode(&car)}
我已经尝试了大部分在StackOverflow和文档中看到的方法，但迄今为止似乎没有任何方法能够解决这个问题。
英文:
I have a table Customers with Cars, and Cars has Services.
When I delete the Car I also want to delete the Services from the database
And when I delete the Customer I want to be able to delete Customer, its Cars, Its Services.
I tried the following to delete Car and Services related to the Car, but it only deletes the Car from the database, how do I delete both Cars and its Services?
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type Customer struct {gorm.ModelFirstName stringLastName stringPhone string `gorm:"typevarchar(100);unique_index"`Cars []Car `gorm:"constraint:OnDelete:CASCADE;"`}type Car struct {gorm.ModelMake stringModelo stringColor stringVinNumber string `gorm:"typevarchar(100);unique_index"`Services []*Service `gorm:"constraint:OnDelete:CASCADE;"`CustomerId int}type Service struct {gorm.ModelComment stringMiles stringCarId int}//endpoints//delete customerfunc deleteCustomer(w http.ResponseWriter, r *http.Request) {params := mux.Vars(r)setupResponse(&w, r)if (*r).Method == "OPTIONS" {return}var customer Customerdb.First(&customer, params["id"])db.Unscoped().Delete(&customer)json.NewEncoder(w).Encode(&customer)}func deleteCar(w http.ResponseWriter, r *http.Request) {setupResponse(&w, r)if (*r).Method == "OPTIONS" {return}params := mux.Vars(r)var car Cardb.First(&car, params["id"])db.Select("Services").Unscoped().Delete(&car)json.NewEncoder(w).Encode(&car)}
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I already tried most of what I seen in StackOverflow and the docs but nothing seems to work so far.
答案1
得分: 0
在阅读了文档和一堆StackOverflow答案后，对我来说没有什么真正有效的方法。文档和/或StackOverflow建议我在迁移模型时添加约束，或者在结构体gorm:"constraint:OnDelete:CASCADE;"中添加约束，我还尝试了db.Select("cars").Delete(&customers)，但没有成功。这是我处理的方式，不确定是否是最佳实践，但它会从数据库中删除相关记录。
我像这样更新了deleteCustomer和deleteCar端点：
//删除客户func deleteCustomer(w http.ResponseWriter, r *http.Request) {params := mux.Vars(r)setupResponse(&w, r)if (*r).Method == "OPTIONS" {return}var customer Customervar cars []Cardb.First(&customer, params["id"])db.Model(&customer).Related(&cars)deleteServicesSqlStatement := `DELETE FROM servicesWHERE car_id = $1;`for i, car := range cars {fmt.Println(i, car.ID)err := db.Exec(deleteServicesSqlStatement, car.ID).Errorif err != nil {fmt.Println(err)}}DeleteCarsSqlStatement := `DELETE FROM carsWHERE customer_id = $1;`err := db.Exec(DeleteCarsSqlStatement, params["id"]).Errorif err != nil {fmt.Println(err)}db.Debug().Unscoped().Delete(&customer)json.NewEncoder(w).Encode(&customer)}//删除汽车func deleteCar(w http.ResponseWriter, r *http.Request) {//处理CORSsetupResponse(&w, r)if (*r).Method == "OPTIONS" {return}params := mux.Vars(r)var car Cardb.First(&car, params["id"])sqlStatement := `DELETE FROM servicesWHERE car_id = $1;`err := db.Exec(sqlStatement, params["id"]).Errorif err != nil {fmt.Println(err)}db.Debug().Unscoped().Delete(&car)json.NewEncoder(w).Encode(&car)}
希望对你有帮助！
英文:
After reading the docs and a bunch of StackOverflow answers nothing really worked for me. The docs and/or StackOverflow suggested I add constraints when I migrated the models, or/and add the constraints to the structs gorm:"constraint:OnDelete:CASCADE;"
, I also tried db.Select("cars").Delete(&customers) with no success. This is how I went about it, not sure if it's the best practice but it deletes its related records from the database.
I updated the deleteCustomer and deleteCar endpoint like this:
<!-- begin snippet: js hide: false console: true babel: false -->
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//delete customerfunc deleteCustomer(w http.ResponseWriter, r *http.Request) {params := mux.Vars(r)setupResponse(&w, r)if (*r).Method == "OPTIONS" {return}var customer Customervar cars []Cardb.First(&customer, params["id"])db.Model(&customer).Related(&cars)deleteServicesSqlStatement := `DELETE FROM servicesWHERE car_id = $1;`for i, car := range cars {fmt.Println(i, car.ID)err := db.Exec(deleteServicesSqlStatement, car.ID).Errorif err != nil {fmt.Println(err)}}DeleteCarsSqlStatement := `DELETE FROM carsWHERE customer_id = $1;`err := db.Exec(DeleteCarsSqlStatement, params["id"]).Errorif err != nil {fmt.Println(err)}db.Debug().Unscoped().Delete(&customer)json.NewEncoder(w).Encode(&customer)}//delete carfunc deleteCar(w http.ResponseWriter, r *http.Request) {//handle CORSsetupResponse(&w, r)if (*r).Method == "OPTIONS" {return}params := mux.Vars(r)var car Cardb.First(&car, params["id"])sqlStatement := `DELETE FROM servicesWHERE car_id = $1;`err := db.Exec(sqlStatement, params["id"]).Errorif err != nil {fmt.Println(err)}db.Debug().Unscoped().Delete(&car)json.NewEncoder(w).Encode(&car)}
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