You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '0

Did you mean to write CREATE TABLE catsub1..., without the $?

Is the table name catsub1, or are you trying to insert the value of the $catsub1 variable as the table name? In this case, you need to set the value of $catsub1 properly because apparently it is now 0.

$catsub1 = "your_table_name";
$sql = "CREATE TABLE $catsub1 ...";