gorm/join_table.go

43 lines
1.2 KiB
Go

package gorm
import (
"fmt"
"strings"
)
type JoinTableHandler interface {
Add(*DB, *Relationship, interface{}, interface{}) error
Delete(*DB, *Relationship) error
Scope(*DB, *Relationship) *DB
}
type defaultJoinTableHandler struct{}
func (*defaultJoinTableHandler) Add(db *DB, relationship *Relationship, foreignValue interface{}, associationValue interface{}) error {
scope := db.NewScope("")
quotedForeignDBName := scope.Quote(relationship.ForeignDBName)
quotedAssociationDBName := scope.Quote(relationship.AssociationForeignDBName)
sql := fmt.Sprintf(
"INSERT INTO %v (%v) SELECT ?,? %v WHERE NOT EXISTS (SELECT * FROM %v WHERE %v = ? AND %v = ?);",
scope.Quote(relationship.JoinTable),
strings.Join([]string{quotedForeignDBName, quotedAssociationDBName}, ","),
scope.Dialect().SelectFromDummyTable(),
scope.Quote(relationship.JoinTable),
quotedForeignDBName,
quotedAssociationDBName,
)
return db.Exec(sql, foreignValue, associationValue, foreignValue, associationValue).Error
}
func (*defaultJoinTableHandler) Delete(db *DB, relationship *Relationship) error {
return db.Delete("").Error
}
func (*defaultJoinTableHandler) Scope(db *DB, relationship *Relationship) *DB {
return db
}
var DefaultJoinTableHandler = &defaultJoinTableHandler{}