MySQL Proc Call - 设置奇怪的行为

Question

我有一个 table 有点像这样：

人数

number = int, cod = int

SELECT * FROM number WHERE number = 21377 and cod = 55; returns 正确值；

所以我有一个 proc 调用要插入：

CREATE DEFINER=`root`@`%` PROCEDURE `create`(IN Numb INT, IN Cod INT, IN qt INT)
BEGIN
    SET @Cont = 0;
    SET @Init = Numb;   
    WHILE @Cont < qt DO
      SET @Exist = (SELECT count(number) FROM rnumber WHERE number = @Init AND cod = Cod LIMIT 1);  
        IF @Exist = 0 THEN
             INSERT INTO (...)
        END IF;
      SET @Cont = @Cont + 1;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
      SET @IniT = @Init + 1;
  END WHILE;  
END$$

呼叫 create (21377, 54, 1);

总是给我变量@Exist 为 1，所以不要继续 if，即使 number 和 cod 的组合不存在。

谁能指出我做错了什么？谢谢。

Answer 1

尝试使用 select into 而不是 set xx = (select...).

同时 cod = Cod 将始终 return 正确...

您还需要声明您的变量...

试试这个：

CREATE DEFINER=`root`@`%` PROCEDURE `create`(IN p_Numb INT, IN p_Cod INT, IN p_qt INT)
BEGIN
declare v_Exist integer;
declare v_Init integer;
declare v_Exist integer;
    SET v_Cont = 0;
    SET v_Exist = 0;
    SET v_Init = p_Numb;   
    WHILE v_Cont < p_qt DO
      SELECT count(number) into v_Exist FROM rnumber WHERE number = v_Init AND cod = p_Cod LIMIT 1;  
        IF v_Exist = 0 THEN
             INSERT INTO (...)
        END IF;
      SET v_Cont = v_Cont +1;                    
      SET v_IniT = v_Init + 1;
  END WHILE;  
END$$

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mysql

stored-procedures