mysql - if else在mysql的存储过程中

Question

大家好，我有点困惑。我只想问这是否是正确的语法。我在其他帖子中尝试了 if else stored proc 查询，但它不起作用。

CREATE PROCEDURE `addBarberCommission`(IN `empID` INT, IN `ioIN` VARCHAR(11))
BEGIN
INSERT INTO `attendance_log` (`emp_id`, `io`) VALUES (`empID`, `ioIN`);
IF (SELECT e.position, e.status, a.io FROM employee e INNER JOIN
attendance_log a WHERE a.emp_id = `empID`
AND e.position = 'Barber'
AND e.status = 'Active'
AND a.io = 'Time In') THEN
INSERT INTO `barber_employee` (`emp_id`, `tot_sal`) VALUES (`empID`, 0);
END IF;
END #

该过程有效，但是当我调用该存储过程时，CALL addBarberCommission(1, 'Time In'); 它会产生一个

ERROR CODE: 1241. Operand should contain 1 column(s)

我只是要求澄清。谢谢

Answer 1

你需要使用EXISTS:

CREATE PROCEDURE `addBarberCommission`(IN `empID` INT, IN `ioIN` VARCHAR(11))
BEGIN
INSERT INTO `attendance_log` (`emp_id`, `io`) VALUES (`empID`, `ioIN`);
IF EXISTS (SELECT e.position, e.status, a.io    --here
           FROM employee e 
           JOIN  attendance_log a 
           WHERE a.emp_id = `empID`
             AND e.position = 'Barber'
             AND e.status = 'Active'
             AND a.io = 'Time In') THEN
  INSERT INTO `barber_employee` (`emp_id`, `tot_sal`) VALUES (`empID`, 0);
END IF;
END #

DBFiddle Demo