英文:
How to delete association (many2many)?
问题
奇怪的行为发生在删除关联时。
查询生成了一个额外的条件，我没有添加。
type Client struct {gorm.ModelName string `gorm:"unique;not null" validate:"required,min=1,max=30"`Kyc_status string `gorm:"not null" validate:"required,min=1,max=30"`Kyc_remarks string `gorm:"default:null" validate:"omitempty,min=0,max=200"`Operators []*Operator `gorm:"many2many:client_operators;"`Op_ids []string `gorm:"-:all" validate:"omitempty,dive,numeric"` // 占位字段，不会成为表的一部分}type Operator struct {gorm.ModelTitle string `gorm:"unique;not null" validate:"required,min=1,max=100"`Email string `gorm:"not null" validate:"required,email"`Mobile string `gorm:"not null" validate:"required,min=7,max=15,numeric"`Last_online time.Time `gorm:"default:null" validate:"omitempty"`Last_ip string `gorm:"default:null" validate:"omitempty,ip"`Clients []*Client `gorm:"many2many:client_operators;"`Cli_ids []string `gorm:"-:all" validate:"omitempty,dive,numeric"`}// 查找与客户相关的运营商var client_query *ClientDBconnection.Where("id = ?", pk).Preload("Operators").First(&client_query)// 删除与客户相关的运营商DBconnection.Model(&Client{}).Where("client_id = ?", pk).Association("Operators").Delete(&client_query.Operators)
我期望的删除操作是：
[2.000ms] [rows:0] DELETE FROM client_operators WHERE client_id = 5 AND client_operators.operator_id = 1
或者
[2.000ms] [rows:0] DELETE FROM client_operators WHERE client_operators.client_id = 5 AND client_operators.operator_id = 1
但实际上它执行的是：
[2.000ms] [rows:0] DELETE FROM client_operators WHERE client_id = 5 AND client_operators.client_id IN (NULL) AND client_operators.operator_id = 1
它添加了额外的条件 " AND client_operators.client_id IN (NULL) "。
我尝试了 Association().Clear()，但也没有起作用。
英文:
Strange behaviour deleting association happened.
The query generated an extra condition which i did not add.
type Client struct {gorm.ModelName string `gorm:"unique;not null" validate:"required,min=1,max=30"`Kyc_status string `gorm:"not null" validate:"required,min=1,max=30"`Kyc_remarks string `gorm:"default:null" validate:"omitempty,min=0,max=200"`Operators []*Operator `gorm:"many2many:client_operators;"`Op_ids []string `gorm:"-:all" validate:"omitempty,dive,numeric"` // placeholder field, wont be part of table}type Operator struct {gorm.ModelTitle string `gorm:"unique;not null" validate:"required,min=1,max=100"`Email string `gorm:"not null" validate:"required,email"`Mobile string `gorm:"not null" validate:"required,min=7,max=15,numeric"`Last_online time.Time `gorm:"default:null" validate:"omitempty"`Last_ip string `gorm:"default:null" validate:"omitempty,ip"`Clients []*Client `gorm:"many2many:client_operators;"`Cli_ids []string `gorm:"-:all" validate:"omitempty,dive,numeric"`}// find operators related to clientvar client_query *ClientDBconnection.Where("id = ?", pk).Preload("Operators").First(&client_query)// delete operators related to clientDBconnection.Model(&Client{}).Where("client_id = ?", pk).Association("Operators").Delete(&client_query.Operators)
I expect the deletion to be:
[2.000ms] [rows:0] DELETE FROM `client_operators` WHERE client_id = 5 AND `client_operators`.`operator_id` = 1
OR
[2.000ms] [rows:0] DELETE FROM `client_operators` WHERE `client_operators`.`client_id` = 5 AND `client_operators`.`operator_id` = 1
However it currently does:
[2.000ms] [rows:0] DELETE FROM `client_operators` WHERE client_id = 5 AND `client_operators`.`client_id` IN (NULL) AND `client_operators`.`operator_id` = 1
It adds the extra condition of " AND `client_operators`.`client_id` IN (NULL) "
I tried Association().Clear() and did not do anything too.
答案1
得分: 1
这是因为你将&Client{}传递给了Model。
根据gorm文档，你需要首先构建一个具有有效Id的客户端，像这样：
type Client struct {gorm.ModelName string `gorm:"unique;not null" validate:"required,min=1,max=30"`Kyc_status string `gorm:"not null" validate:"required,min=1,max=30"`Kyc_remarks string `gorm:"default:null" validate:"omitempty,min=0,max=200"`Operators []*Operator `gorm:"many2many:client_operators;"`Op_ids []string `gorm:"-:all" validate:"omitempty,dive,numeric"` // 占位字段，不会成为表的一部分}type Operator struct {gorm.ModelTitle string `gorm:"unique;not null" validate:"required,min=1,max=100"`Email string `gorm:"not null" validate:"required,email"`Mobile string `gorm:"not null" validate:"required,min=7,max=15,numeric"`Last_online time.Time `gorm:"default:null" validate:"omitempty"`Last_ip string `gorm:"default:null" validate:"omitempty,ip"`Clients []*Client `gorm:"many2many:client_operators;"`Cli_ids []string `gorm:"-:all" validate:"omitempty,dive,numeric"`}// 查找与客户端相关的运营商var client_query *ClientDBconnection.Where("id = ?", pk).Preload("Operators").First(&client_query)// 删除与客户端相关的运营商DBconnection.Model(&Client{ID: pk}).Association("Operators").Delete(&client_query.Operators)
英文:
This is happening because you're passing &Client{} to Model.
Looking at gorm docs you need to construct a client with a valid Id first like this:
type Client struct {gorm.ModelName string `gorm:"unique;not null" validate:"required,min=1,max=30"`Kyc_status string `gorm:"not null" validate:"required,min=1,max=30"`Kyc_remarks string `gorm:"default:null" validate:"omitempty,min=0,max=200"`Operators []*Operator `gorm:"many2many:client_operators;"`Op_ids []string `gorm:"-:all" validate:"omitempty,dive,numeric"` // placeholder field, wont be part of table}type Operator struct {gorm.ModelTitle string `gorm:"unique;not null" validate:"required,min=1,max=100"`Email string `gorm:"not null" validate:"required,email"`Mobile string `gorm:"not null" validate:"required,min=7,max=15,numeric"`Last_online time.Time `gorm:"default:null" validate:"omitempty"`Last_ip string `gorm:"default:null" validate:"omitempty,ip"`Clients []*Client `gorm:"many2many:client_operators;"`Cli_ids []string `gorm:"-:all" validate:"omitempty,dive,numeric"`}// find operators related to clientvar client_query *ClientDBconnection.Where("id = ?", pk).Preload("Operators").First(&client_query)// delete operators related to clientDBconnection.Model(&Client{ID: pk}).Association("Operators").Delete(&client_query.Operators)
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