首先看一个存储过程，这个存储过程是为了构造数据使用的。当然贴出来的存储过程简化了一些不必要的表结构。

CREATE PROCEDURE modifyRootEntry()

BEGIN

DECLARE done INT DEFAULT FALSE;

DECLARE userId INT;

DECLARE userIdIter CURSOR FOR SELECT DISTINCT user_id from entries;

OPEN userIdIter;

read_loop: LOOP

FETCH userIdIter INTO userId;

IF done THEN

LEAVE read_loop;

END IF;

INSERT INTO entries (id, name, user_id, parent_id) VALUES(0, 'root_parent', userId, 0);

UPDATE entries SET parent_id=0 where user_id=userId AND name='file_root' AND parent_id is NULL;

END LOOP;

CLOSE userIdIter;

END;

CREATE PROCEDURE modifyRootEntry()

BEGIN

DECLARE done INT DEFAULT FALSE;

DECLARE userId INT;

DECLARE userIdIter CURSOR FOR SELECT DISTINCT user_id from entries;

START TRANSACTION; // here !

OPEN userIdIter;

read_loop: LOOP

FETCH userIdIter INTO userId;

IF done THEN

LEAVE read_loop;

END IF;

INSERT INTO entries (id, name, user_id, parent_id) VALUES(0, 'root_parent', userId, 0);

UPDATE entries SET parent_id=0 where user_id=userId AND name='file_root' AND parent_id is NULL;

END LOOP;

CLOSE userIdIter;

COMMIT;// here !

END;

UPDATE entries SET parent_id=0 where user_id=userId AND name='file_root' AND parent_id is NULL;

CREATE PROCEDURE modifyRootEntry()

BEGIN

DECLARE done INT DEFAULT FALSE;

DECLARE userId INT;

DECLARE userIdIter CURSOR FOR SELECT DISTINCT user_id from entries;

START TRANSACTION; // here !

OPEN userIdIter;

read_loop: LOOP

FETCH userIdIter INTO userId;

IF done THEN

LEAVE read_loop;

END IF;

INSERT INTO entries (id, name, user_id, parent_id) VALUES(0, 'root_parent', userId, 0);

END LOOP;

UPDATE entries SET parent_id=0 where user_id=userId AND name='file_root' AND parent_id is NULL; // here!

CLOSE userIdIter;

COMMIT;// here !

END;

CREATE PROCEDURE pFastCreateNums (cnt INT UNSIGNED)

BEGIN

DECLARE s INT UNSIGNED DEFAULT 1;

TRUNCATE TABLE Nums;

INSERT INTO Nums SELECT s;

WHILE s*2 <= cnt DO

BEGIN

INSERT INTO Nums SELECT a+s FROM Nums;

SET s = s*2;

END;

END WHILE;

END;