field IsNull, IsNotNull methods

pgm.go

@@ -73,6 +73,16 @@ func (f Field) Trim() Field {
 	return Field("TRIM(" + f.String() + ")")
 }
 
+func (f Field) IsNull() Conditioner {
+	col := f.String()
+	return &Cond{Field: col, op: " IS NULL", len: len(col) + 8}
+}
+
+func (f Field) IsNotNull() Conditioner {
+	col := f.String()
+	return &Cond{Field: col, op: " IS NOT NULL", len: len(col) + 12}
+}
+
 // Eq is equal
 func (f Field) Eq(val any) Conditioner {
 	col := f.String()

playground/qry_select_test.go

@@ -30,6 +30,7 @@ func TestQryBuilder2(t *testing.T) {
 		Where(
 			user.LastName.NEq(7),
 			user.Phone.Like("%123%"),
+			user.UpdatedAt.IsNotNull(),
 			user.Email.NotInSubQuery(db.User.Select(user.ID).Where(user.ID.Eq(123))),
 		).
 		Limit(10).
@@ -39,7 +40,7 @@ func TestQryBuilder2(t *testing.T) {
 	expected := "SELECT users.email, users.first_name FROM users JOIN user_sessions ON users.id = user_sessions.user_id" +
 		" JOIN branch_users ON users.id = branch_users.user_id WHERE users.id = $1 AND (users.status_id = $2 OR users.updated_at = $3)" +
 		" AND users.mfa_kind = $4 AND (users.first_name = $5 OR users.middle_name = $6) AND users.last_name != $7 AND users.phone" +
-		" LIKE $8 AND users.email NOT IN(SELECT users.id FROM users WHERE users.id = $9) LIMIT 10 OFFSET 100"
+		" LIKE $8 AND users.updated_at IS NOT NULL AND users.email NOT IN(SELECT users.id FROM users WHERE users.id = $9) LIMIT 10 OFFSET 100"
 	if expected != got {
 		t.Errorf("\nexpected: %q\ngot: %q", expected, got)
 	}

qry.go

@@ -208,12 +208,16 @@ func (cv *Cond) Condition(args *[]any, argIdx int) string {
 	}
 
 	// 2. normal condition
-	*args = append(*args, cv.Val)
 	var op string
-	if strings.HasSuffix(cv.op, "$") {
-		op = cv.op + strconv.Itoa(argIdx+1)
+	if cv.Val != nil {
+		*args = append(*args, cv.Val)
+		if strings.HasSuffix(cv.op, "$") {
+			op = cv.op + strconv.Itoa(argIdx+1)
+		} else {
+			op = strings.Replace(cv.op, "$", "$"+strconv.Itoa(argIdx+1), 1)
+		}
 	} else {
-		op = strings.Replace(cv.op, "$", "$"+strconv.Itoa(argIdx+1), 1)
+		op = cv.op
 	}
 
 	if cv.action == CondActionNeedToClose {