Question

我是MySQL功能的新手。我创建了一个函数：

CREATE FUNCTION `tems`.`<function_name>`(IN bid INT, IN cid INT)
RETURNS INT(10)
LANGUAGE SQL
NOT DETERMINISTIC
CONTAINS SQL
SQL SECURITY DEFINER
COMMENT ''
BEGIN
DECLARE min_no INT;
SELECT COALESCE(min(number),1)
FROM
  (SELECT r1.number -1 AS number, r1.branch_id, r1.course_id
  FROM `Room` AS r1
  LEFT JOIN `Room` AS r2
    ON r1.branch_id = r2.branch_id 
      AND r1.course_id = r2.course_id
      AND (r1.number - 1) = r2.number
  WHERE r1.number > 1 AND r2.number IS NULL
  UNION ALL
  SELECT max(number) + 1, branch_id, course_id
  FROM `Room`
  GROUP BY branch_id, course_id) AS q
WHERE branch_id=bid AND course_id=cid
GROUP BY branch_id, course_id
INTO min_no;
RETURN (min_no);
END;

我想获得bid，cid并返回选择值，但我收到了错误消息：

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'IN bid INT, IN cid INT)
RETURNS INT(10)
LANGUAGE SQL
NOT DETERMINISTIC
CONTAINS ' at line 1

我做错了什么？

Answer 1

使用下面的DELIMITER以及删除两部分标识符。只需声明函数名称。

DELIMITER $$
CREATE FUNCTION MyTestFunc (bid INT, cid INT)
RETURNS INT(10)
LANGUAGE SQL
NOT DETERMINISTIC
CONTAINS SQL
SQL SECURITY DEFINER
COMMENT ''
BEGIN
DECLARE min_no INT;
SELECT COALESCE(min(number),1)
FROM
  (SELECT r1.number -1 AS number, r1.branch_id, r1.course_id
  FROM `Room` AS r1
  LEFT JOIN `Room` AS r2
    ON r1.branch_id = r2.branch_id 
      AND r1.course_id = r2.course_id
      AND (r1.number - 1) = r2.number
  WHERE r1.number > 1 AND r2.number IS NULL
  UNION ALL
  SELECT max(number) + 1, branch_id, course_id
  FROM `Room`
  GROUP BY branch_id, course_id) AS q
WHERE branch_id=bid AND course_id=cid
GROUP BY branch_id, course_id
INTO min_no;
RETURN (min_no);
END$$
DELIMITER ;

将MySQL查询存储为函数

1 个答案: