在MySQL中使用遊標的存儲過程

Question

我可以在MySQL中使用存儲過程的遊標嗎？我可以從中獲得輸出值嗎？

Answer 1

是;

CREATE PROCEDURE curdemo() 
BEGIN 
    DECLARE done INT DEFAULT 0; 
    DECLARE a CHAR(16); 
    DECLARE b,c INT; 
    DECLARE cur1 CURSOR FOR SELECT id,data FROM test.t1; 
    DECLARE cur2 CURSOR FOR SELECT i FROM test.t2; 
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1; 

    OPEN cur1; 
    OPEN cur2; 

    REPEAT 
    FETCH cur1 INTO a, b; 
    FETCH cur2 INTO c; 
    IF NOT done THEN 
     IF b < c THEN 
      INSERT INTO test.t3 VALUES (a,b); 
     ELSE 
      INSERT INTO test.t3 VALUES (a,c); 
     END IF; 
    END IF; 
    UNTIL done END REPEAT; 

    CLOSE cur1; 
    CLOSE cur2; 
END 

取自the manual的示例。