MYSQL modifie toutes les tables d'une base

USE INFORMATION_SCHEMA;
SELECT 
CONCAT("ALTER TABLE ", TABLE_SCHEMA ,".", TABLE_NAME, "ENGINE=MEMORY;") 
AS MySQLCMD FROM TABLES 
WHERE TABLE_SCHEMA = "MA_BASE";

Liste tous les champs d'une table dans un tableau PHP

USE INFORMATION_SCHEMA;
SELECT 
CONCAT('$variable["', COLUMN_NAME ,'"]') 
FROM COLUMNS 
WHERE TABLE_SCHEMA = "mabase" AND TABLE_NAME='matable';