Question

创建临时表时，我遇到圆函数问题。（好吧，我认为无论如何这都是问题）

下面列表中的“EntryGauge”列需要根据数据库中的另一个值（不同的表）进行缩放和舍入。

我认为有2个查询可用作子查询来检索比例因子和舍入精度值。当我尝试使用它们时（如下面的查询中所示），会出现此错误：

“SQL错误（1166）：列名不正确'ROUND（EntryGauge *（SELECT DisplayScaleFactor FROM webreportparametersetup WHERE MachineIdent ='Mac'”

我不确定问题是什么，或者我是否正确使用子查询但我真的可以使用一些帮助！

DROP TEMPORARY TABLE IF EXISTS LiveFeed;
CREATE TEMPORARY TABLE LiveFeed AS
(
SELECT 
    MachineIdent, 
    CoilID, 
    DATE_FORMAT(StartTime, '%b %d %Y %h:%i %p'), 
    DATE_FORMAT(EndTime, '%b %d %Y %h:%i %p'), 
    TIMEDIFF(EndTime, StartTime), 
    Alloy,
    ROUND(EntryGauge * (SELECT DisplayScaleFactor FROM webreportparametersetup WHERE MachineIdent = 'MachineIdent' AND ItemName = 'EntryGauge'), (SELECT DisplayPrecision FROM webreportparametersetup WHERE MachineIdent = 'MachineIdent' AND ItemName = 'EntryGauge')), 
    ExitGauge, 
    EntryWidth, 
    ExitWidth, 
    CoilDiameter, 
    CoilLength 
FROM Coil 
    INNER JOIN CoilPass 
    ON Coil.CoilIdent=CoilPass.CoilIdent 
    INNER JOIN PassSection
    ON CoilPass.PassIdent=PassSection.PassIdent 
WHERE PassSection.SectionIdent IN('7965','7966','7967')
);

修改：要清楚计算需要的内容：

Round（EntryGauge * ScaleFactor，RoundingPrecision）

Answer 1

请试试这个：

ROUND(EntryGauge * (SELECT DisplayScaleFactor 
FROM webreportparametersetup WHERE MachineIdent = 'MachineIdent' 
AND ItemName = 'EntryGauge'),2), ROUND((SELECT DisplayPrecision 
FROM webreportparametersetup WHERE MachineIdent = 'MachineIdent' 
AND ItemName = 'EntryGauge'),2)

我认为这是括号中的问题

Answer 2

也许你只是忘了给圆柱一个名字？加入为您提供了更好的概述：

DROP TEMPORARY TABLE IF EXISTS LiveFeed;
CREATE TEMPORARY TABLE LiveFeed AS
(
SELECT 
    MachineIdent, 
    CoilID, 
    DATE_FORMAT(StartTime, '%b %d %Y %h:%i %p'), 
    DATE_FORMAT(EndTime, '%b %d %Y %h:%i %p'), 
    TIMEDIFF(EndTime, StartTime), 
    Alloy,
    ROUND(EntryGauge * webreportparametersetup.DisplayScaleFactor,webreportparametersetup.DisplayPrecision) as RoundedValue, 
    ExitGauge, 
    EntryWidth, 
    ExitWidth, 
    CoilDiameter, 
    CoilLength 
FROM Coil 
    INNER JOIN CoilPass 
    ON Coil.CoilIdent=CoilPass.CoilIdent 
    INNER JOIN PassSection
    ON CoilPass.PassIdent=PassSection.PassIdent
    LEFT JOIN webreportparametersetup
    ON MachineIdent = 'MachineIdent' AND ItemName = 'EntryGauge'
WHERE PassSection.SectionIdent IN('7965','7966','7967')
);

MySQL Round＆amp;子查询

2 个答案: