如果没有数据更改，Codeigniter update_batch返回false

Question

I have found something disturbing in codeigniter, why is when I use update_batch and the data to be updated is the exact same as the data in the db, it always return false.

I can't seem to find any logical and good explanation and illustration in the CI documentation. I need it to return true even if there is no data changed, as it affect a great chunk of my codes, and only return false if failed to update db (ie inserting a data that already exist into a unique column), then it should return false.

One more thing, how do I show db query error message in CI ? have read that it should be $this->db->_error_message() , but it keeps returning Call to undefined method . What am I missing here ?

Answer 1

Your questions contain conflicting information:

• update_batch() has never returned boolean false if it has successfully executed at least one UPDATE query, regardless of whether any records were updated or not.
  • In CI2, it had a void return value in that case (implicitly converted to null if you want to use it).
  • In CI3, it returns an integer containing the number of rows affected ( int(0) is not the same thing as bool(false) )
  • In both version trees, boolean false is only returned when you pass incorrect parameters.
• _error_message() used to exist on CI2, but its underscore prefix denotes that it was an internal method and you shouldn't be using it. CI3 has an error() method replacing it, which returns the code and message in an array, if there was an error in the first place.