Question

我正在使用3个表格，Part，PartDrawing和ShopDrawing。基本上我想显示其所有零件都有库存的所有ShopDrawings。但是，每个ShopDrawing都有多个PartDrawings，所以当我运行我的查询时：

SELECT DISTINCT ShopDrawing.DrawingNo FROM ShopDrawing, PartDrawing, Part
WHERE ShopDrawing.DrawingNo = PartDrawing.DrawingNo
AND PartDrawing.PartNo = Part.PartNo
AND Part.InStock = 'YES';

它显示每一个ShopDrawing，因为它们都至少有一个库存的零件。我只想要它显示ShopDrawings，其中所需的所有零件都有库存，我不知道该怎么做。

Answer 1

尝试评估时不选择Part.InStock = 'NO'的数据，而不是选择Part.InStock = 'YES'的数据

SELECT 
     ShopDrawing.DrawingNo 
FROM 
     ShopDrawing WHERE ShopDrawing.DrawingNo NOT IN
         (SELECT 
              PartDrawing.DrawingNo 
          FROM 
              PartDrawing LEFT JOIN Part ON PartDrawing.PartNo = Part.PartNo 
          WHERE 
              Part.InStock IS NULL
          GROUP BY PartDrawing.DrawingNo 
          HAVING COUNT(*)>0)

如果ALL记录与另一个表中的某些内容相等，则尝试显示记录

1 个答案: