syntax for MySQL INSERT with an array of columns
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I'm new to PHP and MySQL query construction. I have a processor for a large form. A few fields are required, most fields are user optional. In my case, the HTML ids and the MySQL column names are identical. I've found tutorials about using arrays to convert $_POST into the fields and values for INSERT INTO, but I can't get them working - after many hours. I've stepped back to make a very simple INSERT using arrays and variables, but I'm still stumped.  The following line works and INSERTs 5 items into a database with over 100 columns. The first 4 items are strings, the 5th item, monthlyRental is an integer.


    $query = "INSERT INTO `$table` (country, stateProvince, city3, city3Geocode, monthlyRental) VALUES ( '$country', '$stateProvince', '$city3', '$city3Geocode', '$monthlyRental')";


When I make an array for the fields and use it, as follows:


    $colsx = array('country,', 'stateProvince,', 'city3,', 'city3Geocode,', 'monthlyRental');
    $query = "INSERT INTO `$table` ('$colsx') VALUES ( '$country', '$stateProvince', '$city3', '$city3Geocode', '$monthlyRental')";

I get a MySQL error - check the manual that corresponds to your MySQL server version for the right syntax to use near ''Array') VALUES ( 'US', 'New York', 'Fairport, Monroe County, New York', '(43.09)' at line 1.  I get this error whether the array items have commas inside the single quotes or not.  I've done a lot of reading and tried many combinations and I can't get it. I want to see the proper syntax on a small scale before I go back to foreach expressions to process $_POST and both the fields and values are arrays. And yes, I know I should use mysql_real_escape_string, but that is an easy later step in the foreach. Lastly, some clues about the syntax for an array of values would be helpful, particularly if it is different from the fields array. I know I need to add a null as the first array item to trigger the MySQL autoincrement id.  What else?

I'm pretty new, so please be specific.