Question

我是sql的初学者，甚至是编程方面的新手，最近我都发现了触发器，并且我想计算活动行的最大数量以及活动权重的总和 ps：活动记录定义为'cancled = 0' 我在声明变量（第2行）的行附近出现了错误＃1064

我正在将其运行到PHPMYADMIN（MySQL）触发器中。

BEGIN
DECLARE @max_rows int;
DECLARE @max_tare int;
SET @max_rows = SELECT COUNT(*) FROM history WHERE cancled = 0;
SET @max_tare= SELECT SUM(tare) FROM history WHERE cancled = 0;
UPDATE max_tare
SET max_row  = @max_rows,
    max_tare = @max_tare
WHERE id = 1
END

我期望我用最大行数和活动权重的总和来更新第1行，但是我有一个错误

MySQL回复：＃1064-'@max_rows int附近的语法错误；宣布 @max_tare int; SET @max_rows =从他的第2行中选择COUNT（*）

在Paul评论后，我将代码更改为：

BEGIN
DECLARE max_r int;
DECLARE max_t int;
SET max_r = SELECT COUNT(*) FROM history WHERE cancled = 0;
SET max_t = SELECT SUM(tare) FROM history WHERE cancled = 0;
UPDATE max_tare
SET max_row  = max_r,
    max_tare = max_t
WHERE id = 1
END

这是新错误：

MySQL回复：＃1064-SELECT COUNT（*）FROM附近的语法错误取消的历史记录= 0; SET max_t =第4行的SELECT SUM（皮重）FR'

提前

ty。

Answer 1

感谢@paul Spiegel和@forpas的帮助这段代码帮助解决了问题

IF(NEW.mix != '') THEN
UPDATE max_tare
SET max_row  = (SELECT COUNT(*)  FROM history WHERE nom LIKE NEW.mix),
    max_tare = (SELECT SUM(tare) FROM history WHERE cancled = 0)
WHERE id = 1;
ELSE
UPDATE max_tare
SET max_row  = (SELECT COUNT(*)  FROM history WHERE cancled = 0),
    max_tare = (SELECT SUM(tare) FROM history WHERE cancled = 0)
WHERE id = 1;
END IF;
END

这对我来说很好，谢谢大家

插入后选择count（*）并选择sum（my_data）-错误语法＃1064

1 个答案: