MySql Optimize all tables

set @a=null,@c=null,@b=concat("show tables where",ifnull(concat(" `Tables_in_",database(),"` like '",@c,"' and"),'')," (@a:=concat_ws(',',@a,`Tables_in_",database(),"`))");

Prepare `bd` from @b;
EXECUTE `bd`;
DEALLOCATE PREPARE `bd`;

set @a:=concat('optimize table ',@a);
PREPARE `sql` FROM @a;
EXECUTE `sql`;
DEALLOCATE PREPARE `sql`;

set @a=null,@b=null,@c=null;