Question

使用MySQL，我试图创建一个存储过程来检索任何给定表中varchar列的最大值。我想将列的值增加1，然后使用它来存储其他字段。我不希望该列为int并自动递增。

我现在拥有的存储过程是 DELIMITER $$

use gounicartdb$$

DROP PROCEDURE IF EXISTS sp_getUpdatedIDFromTable$$

CREATE PROCEDURE sp_getUpdatedIDFromTable(
IN tableName varchar(50),
IN columnName varchar(50),
IN incrementValue int/*,
OUT updatedID varchar(10)*/
)
BEGIN

SET @newID = "abc";

SET @cmdString = concat("Select max(", columnName, ") from ", tableName);

PREPARE stmt FROM @cmdString;

SELECT @newID = EXECUTE stmt;

END$$

DELIMITER ;

编译时我看不到任何错误，但在执行该过程时会发生以下错误。

14:50:48    Call sp_getUpdatedIDFromTable("user", "SNo", 1) Error Code: 1054. Unknown column 'EXECUTE' in 'field list'  0.000 sec

请帮忙。

Answer 1

您可以在程序中替换

SET @cmdString = concat("Select max(", columnName, ") into @newID from ", tableName);
PREPARE stmt FROM @cmdString;
EXECUTE stmt;
SELECT @newID;

无法在mysql中存储execute语句的返回值

1 个答案: