MySql

//Create Table

$sql = "CREATE TABLE rulesdevsce (rdannu char(1) NOT NULL, rdidro int NOT NULL AUTO_INCREMENT, rdidco int, rdacco int, rdscen int, rdacti int, PRIMARY KEY (rdidro))";

//Add field with comment

ALTER TABLE `user` CHANGE `id` `id` INT( 11 ) COMMENT 'id of user'  

$sql = "ALTER TABLE table ADD COLUMN filedname int COMMENT 'my comment'";

//Get table informations

$sql="show full columns from tablename";