Question

I just this error when Im updating database and I dont change any of the values in the form and submit. I would like to know why and suggestion to correct this error.

sample

SELECT * FROM `table` WHERE `id` = 1

  id    =  1,
 name   = John,
 city   = New York;

UPDATE `table` SET name = 'John', city = 'New York' WHERE id = 1

when updating the database with the same values what you select from database and use affected rows i get 0

Answer 1

As the manual states:

For UPDATE statements, the affected-rows value by default is the number of rows actually changed. If you specify the CLIENT_FOUND_ROWS flag to mysql_real_connect() when connecting to mysqld, the affected-rows value is the number of rows “found”; that is, matched by the WHERE clause.

Therefore, because your UPDATE does not actually change any rows, the default affected-rows value is 0.