MySQL returned error

Error Description :

Error No : 1064
Description : You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'AND is_approved = '1')' at line 1

SQL Query
SELECT eco_testimonial.*, user.full_name AS user_full_name, user.name AS user_name, user.surname AS user_surname, user.company_name AS user_company_name, user.user_picture AS user_user_picture, user.gender AS user_gender FROM eco_testimonial LEFT JOIN user AS user ON(user.id=eco_testimonial.feedbackbyuser) WHERE eco_testimonial.id!=0 AND (feedbacktouser = AND is_approved = '1')