SQLite queries with javascript seems to handle strangely the NULL value. INSERT INTO : put a correct NULL in the table SELECT ... WHERE xxxx IS NOT NULL : does not select only NOT NULL rows, but all rows. UPDATE xxx SET yyy = NULL WHERE zzz = 'aaa' : does not update with NULL but with 0. I suppose it comes from the difficulties of max handling the NULL concept? But I'm passing directly the string to sql_obj in javascript, so why should the database not update with NULL???