測試表 level ;
復制代碼代碼如下:
create table test.level (name varchar(20));
再 insert 些數據 ;
代碼
初始化
復制代碼代碼如下:
drop procedure if exists useCursor //
建立 存儲過程 create
復制代碼代碼如下:
CREATE PROCEDURE useCursor()
BEGIN
局部變量的定義 declare
復制代碼代碼如下:
declare tmpName varchar(20) default '' ;
declare allName varchar(255) default '' ;
declare cur1 CURSOR FOR SELECT name FROM test.level ;
MySQL 游標 異常后 捕捉
并設置 循環使用 變量 tmpname 為 null 跳出循環。
復制代碼代碼如下:
declare CONTINUE HANDLER FOR SQLSTATE '02000' SET tmpname = null;
開游標
復制代碼代碼如下:
OPEN cur1;
游標向下走一步
復制代碼代碼如下:
FETCH cur1 INTO tmpName;
循環體 這很明顯 把MySQL 游標查詢出的 name 都加起并用 ; 號隔開
復制代碼代碼如下:
WHILE ( tmpname is not null) DO
set tmpName = CONCAT(tmpName ,";") ;
set allName = CONCAT(allName ,tmpName) ;
游標向下走一步
復制代碼代碼如下:
FETCH cur1 INTO tmpName;
結束循環體:
復制代碼代碼如下:
END WHILE;
關閉游標
復制代碼代碼如下:
CLOSE cur1;
選擇數據
復制代碼代碼如下:
select allName ;
結束存儲過程
復制代碼代碼如下:
END;//
調用存儲過程：
復制代碼代碼如下:
call useCursor()//
運行結果：
復制代碼代碼如下:
mysql> call useCursor()//
+--------------------------------------+
| allName |
+--------------------------------------+
| f1;c3;c6;c5;c2;c4;c1;f1;f3;f4;f2;f5; |
+--------------------------------------+
1 row in set (0.00 sec)
loop循環游標：
復制代碼代碼如下:
DELIMITER $$
DROP PROCEDURE IF EXITS cursor_example$$
CREATE PROCEDURE cursor_example()
READS SQL DATA
BEGIN
DECLARE l_employee_id INT;
DECLARE l_salary NUMERIC(8,2);
DECLARE l_department_id INT;
DECLARE done INT DEFAULT 0;
DECLARE cur1 CURSOR FOR SELECT employee_id, salary, department_id FROM employees;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done=1;
OPEN cur1;
emp_loop: LOOP
FETCH cur1 INTO l_employee_id, l_salary, l_department_id;
IF done=1 THEN
LEAVE emp_loop;
END IF;
END LOOP emp_loop;
CLOSE cur1;
END$$
DELIMITER ;
repeat循環游標：
復制代碼代碼如下:
/*創建過程*/
DELIMITER //
DROP PROCEDURE IF EXISTS test //
CREATE PROCEDURE test()
BEGIN
DECLARE done INT DEFAULT 0;
DECLARE a VARCHAR(200) DEFAULT '';
DECLARE c VARCHAR(200) DEFAULT '';
DECLARE mycursor CURSOR FOR SELECT fusername FROM uchome_friend;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done=1;
OPEN mycursor;
REPEAT
FETCH mycursor INTO a;
IF NOT done THEN
SET c=CONCAT(c,a);/*字符串相加*/
END IF;
UNTIL done END REPEAT;
CLOSE mycursor;
SELECT c;
END //
DELIMITER ;
復制代碼代碼如下:
/*創建過程*/
DELIMITER //
DROP PROCEDURE IF EXISTS test //
CREATE PROCEDURE test()
BEGIN
DECLARE done INT DEFAULT 0;
DECLARE a VARCHAR(200) DEFAULT '';
DECLARE c VARCHAR(200) DEFAULT '';
DECLARE mycursor CURSOR FOR SELECT fusername FROM uchome_friend;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done=1;
OPEN mycursor;
REPEAT
FETCH mycursor INTO a;
IF NOT done THEN
SET c=CONCAT(c,a);/*字符串相加*/
END IF;
UNTIL done END REPEAT;
CLOSE mycursor;
SELECT c;
END //
DELIMITER ;
