Is it possible to alter a table in mySql via stored procedures?

Question

here's what I'd like to do in mySQL... I'm getting the feeling that this is simply not feasible, but would love to be wrong...

create procedure foo(IN MYTABLE varchar(50) , IN COLNAME varchar (50), IN MYTYPE varchar(50)) 
begin 
IF (select count(*) from information_schema.columns where table_name =MYTABLE and column_name = COLNAME) = 0 
THEN
alter table MYTABLE add column MYNAME MYTYPE; 
end;

call foo( 'table_foo' , 'column_bar' , 'varchar(100)' );

Answer 1

Short answer: No.

Long answer: Why? Your data model should not be as fluid as you seem to think you want it to be. Lock it down. Normalize it. If you need arbitrary columnar values, use a User Defined Field pattern. Don't go messing with your tables at a whim. Not a good idea.

Answer 2

Don't know why on Earth you would want it, but it's possible:

DELIMITER //
DROP PROCEDURE foo//
CREATE PROCEDURE foo(IN MYTABLE varchar(50) , IN COLNAME varchar (50), IN MYTYPE varchar(50))
BEGIN
  SET @ddl = CONCAT('alter table ', MYTABLE, ' add column (', COLNAME, ' ', MYTYPE, ')');
  PREPARE STMT FROM @ddl;
  EXECUTE STMT;
END;
//