Mysql_query返回值为1但数据库未受影响

i'm going to update a row into mysql database. the senarius is: taking the values from a form and redirect to another file and set the form values to database using update statement. the problem is that mysql_query return value 1 and does not return any error but when i check the database through phpmyadmin my database doesn't affected. here is the codei'm going to update a row into mysql database.