Question

我有以下SP，它在调用时返回null，但值在数据库中

CREATE PROCEDURE calculate_amount_sum(IN accid INT UNSIGNED, IN tableName VARCHAR(100), IN tablecode VARCHAR(100), OUT calc FLOAT)
READS SQL DATA
BEGIN
SET @GetSql = CONCAT('SELECT SUM(amount) INTO @total FROM ', tableName, ' WHERE code=', ''' , tablecode, ''' , ' AND account_id=', accid);
PREPARE stmt FROM @GetSql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET calc = @total; 
CREATE TEMPORARY TABLE IF NOT EXISTS tempT (`amount` float(10,4) NOT NULL)  ;
INSERT INTO cache values (calc) ;    
INSERT INTO cache values (@total) ;    
END //

错误是

Column 'amount' cannot be null

将值插入tempT表时

可能是什么原因，Thanx提前

Answer 1

替换您的代码如下：

SELECT SUM(IFNULL(amount,0)) INTO @total FROM

Answer 2

最后我改变了这个，然后修好了

 SET @GetSql = CONCAT("SELECT SUM(amount) INTO @total FROM ", tableName, " WHERE code='", tablecode,"' AND account_id=", accid);

谢谢

具有动态表名的Mysql SP调用返回null作为结果

2 个答案: