[Maria-developers] Is it a big? CURSOR does not see changes made by ALTER TABLE

2 Mar 2017

      Hello Elena, all.

I noticed that CURSORs in combination with ALTER TABLE work strange.

Is it a known bug?

Thanks.

-- I create a table with two columns
-- And a procedure fetching two columns from this table

SET sql_mode=DEFAULT;
DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (a INT, b VARCHAR(10));
INSERT INTO t1 VALUES (10,20);

DROP PROCEDURE IF EXISTS p1;
DELIMITER $$
CREATE PROCEDURE p1()
BEGIN
  DECLARE a,b INT;
  DECLARE cur CURSOR FOR SELECT * FROM t1;
  OPEN cur;
  FETCH cur INTO a,b;
  CLOSE cur;
  SELECT a,b;
END;
$$
DELIMITER ;
CALL p1();

-- It returns
-- +------+------+
-- | a    | b    |
-- +------+------+
-- |   10 |   20 |
-- +------+------+
-- So far so good

-- Now I add a new column to the table and call the procedure again
ALTER TABLE t1 ADD c INT;
CALL p1();

-- Woops. It should have failed, because there are now 3 columns in the
table
-- But it returns the result, like if the table still had 2 columns.

[Maria-developers] Is it a big? CURSOR does not see changes made by ALTER TABLE

Alexander Barkov