MySQL动态游标

时间:2021-01-27 09:09:28

通过(准备语句+视图+静态游标)实现

-- 建立测试表和数据
create table webuser (username varchar(10));
insert into webuser values ('a1'),('a2'),('a3'),('b1'),('b2'),('b3');
commit; -- 建立存储过程
drop procedure if exists dynamic_cursor;
delimiter //
CREATE PROCEDURE dynamic_cursor (IN p_name varchar(10))
BEGIN
DECLARE done INT DEFAULT 0;
DECLARE v_username varchar(10);
DECLARE cur CURSOR for( SELECT username from webuser_view);
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1; DROP VIEW IF EXISTS webuser_view; SET @sqlstr = "CREATE VIEW webuser_view as ";
SET @sqlstr = CONCAT(@sqlstr , "SELECT username FROM webuser WHERE username like '", p_name,"%'"); PREPARE stmt FROM @sqlstr;
EXECUTE stmt;
DEALLOCATE PREPARE stmt; OPEN cur;
f_loop:LOOP
FETCH cur INTO v_username;
IF done THEN
LEAVE f_loop;
END IF;
SELECT v_username;
END LOOP f_loop;
CLOSE cur;
END;
//
delimiter ; -- 测试
call dynamic_cursor('a');