Support named Joins, close #3833

callbacks/query.go

@@ -108,7 +108,7 @@ func BuildQuerySQL(db *gorm.DB) {
 			for _, join := range db.Statement.Joins {
 				if db.Statement.Schema == nil {
 					joins = append(joins, clause.Join{
-						Expression: clause.Expr{SQL: join.Name, Vars: join.Conds},
+						Expression: clause.NamedExpr{SQL: join.Name, Vars: join.Conds},
 					})
 				} else if relation, ok := db.Statement.Schema.Relationships.Relations[join.Name]; ok {
 					tableAliasName := relation.Name
@@ -150,7 +150,7 @@ func BuildQuerySQL(db *gorm.DB) {
 					})
 				} else {
 					joins = append(joins, clause.Join{
-						Expression: clause.Expr{SQL: join.Name, Vars: join.Conds},
+						Expression: clause.NamedExpr{SQL: join.Name, Vars: join.Conds},
 					})
 				}
 			}

tests/joins_test.go

@@ -61,35 +61,41 @@ func TestJoinConds(t *testing.T) {
 	DB.Save(&user)
 
 	var users1 []User
-	DB.Joins("left join pets on pets.user_id = users.id").Where("users.name = ?", user.Name).Find(&users1)
+	DB.Joins("inner join pets on pets.user_id = users.id").Where("users.name = ?", user.Name).Find(&users1)
 	if len(users1) != 3 {
 		t.Errorf("should find two users using left join, but got %v", len(users1))
 	}
 
 	var users2 []User
-	DB.Joins("left join pets on pets.user_id = users.id AND pets.name = ?", user.Pets[0].Name).Where("users.name = ?", user.Name).First(&users2)
+	DB.Joins("inner join pets on pets.user_id = users.id AND pets.name = ?", user.Pets[0].Name).Where("users.name = ?", user.Name).First(&users2)
 	if len(users2) != 1 {
 		t.Errorf("should find one users using left join with conditions, but got %v", len(users2))
 	}
 
 	var users3 []User
-	DB.Joins("left join pets on pets.user_id = users.id AND pets.name = ?", user.Pets[0].Name).Joins("join accounts on accounts.user_id = users.id AND accounts.number = ?", user.Account.Number).Where("users.name = ?", user.Name).First(&users3)
+	DB.Joins("inner join pets on pets.user_id = users.id AND pets.name = ?", user.Pets[0].Name).Joins("join accounts on accounts.user_id = users.id AND accounts.number = ?", user.Account.Number).Where("users.name = ?", user.Name).First(&users3)
 	if len(users3) != 1 {
 		t.Errorf("should find one users using multiple left join conditions, but got %v", len(users3))
 	}
 
 	var users4 []User
-	DB.Joins("left join pets on pets.user_id = users.id AND pets.name = ?", user.Pets[0].Name).Joins("join accounts on accounts.user_id = users.id AND accounts.number = ?", user.Account.Number+"non-exist").Where("users.name = ?", user.Name).First(&users4)
+	DB.Joins("inner join pets on pets.user_id = users.id AND pets.name = ?", user.Pets[0].Name).Joins("join accounts on accounts.user_id = users.id AND accounts.number = ?", user.Account.Number+"non-exist").Where("users.name = ?", user.Name).First(&users4)
 	if len(users4) != 0 {
 		t.Errorf("should find no user when searching with unexisting credit card, but got %v", len(users4))
 	}
 
 	var users5 []User
-	db5 := DB.Joins("left join pets on pets.user_id = users.id AND pets.name = ?", user.Pets[0].Name).Joins("join accounts on accounts.user_id = users.id AND accounts.number = ?", user.Account.Number).Where(User{Model: gorm.Model{ID: 1}}).Where(Account{Model: gorm.Model{ID: 1}}).Not(Pet{Model: gorm.Model{ID: 1}}).Find(&users5)
+	db5 := DB.Joins("inner join pets on pets.user_id = users.id AND pets.name = ?", user.Pets[0].Name).Joins("join accounts on accounts.user_id = users.id AND accounts.number = ?", user.Account.Number).Where(User{Model: gorm.Model{ID: 1}}).Where(Account{Model: gorm.Model{ID: 1}}).Not(Pet{Model: gorm.Model{ID: 1}}).Find(&users5)
 	if db5.Error != nil {
 		t.Errorf("Should not raise error for join where identical fields in different tables. Error: %s", db5.Error.Error())
 	}
 
+	var users6 []User
+	DB.Joins("inner join pets on pets.user_id = users.id AND pets.name = @Name", user.Pets[0]).Where("users.name = ?", user.Name).First(&users6)
+	if len(users6) != 1 {
+		t.Errorf("should find one users using left join with conditions, but got %v", len(users6))
+	}
+
 	dryDB := DB.Session(&gorm.Session{DryRun: true})
 	stmt := dryDB.Joins("left join pets on pets.user_id = users.id AND pets.name = ?", user.Pets[0].Name).Joins("join accounts on accounts.user_id = users.id AND accounts.number = ?", user.Account.Number).Where(User{Model: gorm.Model{ID: 1}}).Where(Account{Model: gorm.Model{ID: 1}}).Not(Pet{Model: gorm.Model{ID: 1}}).Find(&users5).Statement