mysql - 是否可以通过存储过程更改 mySql 中的表？

Question

这就是我想在 mySQL 中做的事情...我感觉这根本不可行，但很想错...

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

不知道为什么你会想要它，但这是可能的:

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;
//