Heim >Datenbank >MySQL-Tutorial >mysql存储过程加速
欢迎进入Linux社区论坛,与200万技术人员互动交流 >>进入 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 u
欢迎进入Linux社区论坛,与200万技术人员互动交流 >>进入
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
BEGIN
INSERT INTO Nums SELECT a+s FROM Nums;
SET s = s*2;
END;
END WHILE;
END;