Sql 带计算列的Where子句

您好，我想在这里添加一个条件，如

where Date介于..

和

salercentage>50之间，但它salercentage不是db中的一列，它只是像下面的代码中一样强制转换

我怎么用呢。提前谢谢

      var sql = @"SELECT TOP 10 
                    sp.ProductName, 
                    SUM(sp.QtySold) AS QtySold,
                    SUM(r.QtyinPieces) AS StockLimit,                  
                    CAST(    (CAST    (SUM(sp.QtySold) AS FLOAT)     /    CAST(SUM(r.QtyinPieces) AS FLOAT)  ) * 100 AS DECIMAL(8,2)       ) [SalesPercentage]
                FROM 
                    Sales_productholder sp
                    JOIN Orders_productholder r ON (sp.ProductID = r.ProductID)

                GROUP BY 
                    sp.ProductName, r.ProductID, r.QtyinPieces
                ORDER BY 
                    SUM(sp.QtySold) DESC";

更新：我有一个组合框，里面有像5、10、20这样的项目，我想把它作为
Top5
的参数。但它总是导致错误
顶部附近的语法错误

以下是我尝试过的：

选择TOP@TOP

command.Parameters.AddWithValue("@Top", cboTop.SelectedItem.ToString());

及

您可以像这样添加
具有

HAVING
    CAST( (CAST ( SUM(sp.QtySold) AS FLOAT) / CAST(SUM(r.QtyinPieces) AS FLOAT) ) * 100 AS DECIMAL(8,2) ) > 50

所有查询：

SELECT TOP 10 
    sp.ProductName, 
    SUM(sp.QtySold) AS QtySold,
    SUM(r.QtyinPieces) AS StockLimit,                  
    CAST( (CAST ( SUM(sp.QtySold) AS FLOAT) / CAST(SUM(r.QtyinPieces) AS FLOAT) ) * 100 AS DECIMAL(8,2) ) [SalesPercentage]
FROM 
    Sales_productholder sp
    JOIN Orders_productholder r ON (sp.ProductID = r.ProductID)
WHERE [Date] between @DateBegin and @DateAdd
GROUP BY 
    sp.ProductName, r.ProductID, r.QtyinPieces
HAVING
    CAST( (CAST ( SUM(sp.QtySold) AS FLOAT) / CAST(SUM(r.QtyinPieces) AS FLOAT) ) * 100 AS DECIMAL(8,2) ) > 50
ORDER BY 
    SUM(sp.QtySold) DESC

您可以像这样添加
具有

HAVING
    CAST( (CAST ( SUM(sp.QtySold) AS FLOAT) / CAST(SUM(r.QtyinPieces) AS FLOAT) ) * 100 AS DECIMAL(8,2) ) > 50

所有查询：

SELECT TOP 10 
    sp.ProductName, 
    SUM(sp.QtySold) AS QtySold,
    SUM(r.QtyinPieces) AS StockLimit,                  
    CAST( (CAST ( SUM(sp.QtySold) AS FLOAT) / CAST(SUM(r.QtyinPieces) AS FLOAT) ) * 100 AS DECIMAL(8,2) ) [SalesPercentage]
FROM 
    Sales_productholder sp
    JOIN Orders_productholder r ON (sp.ProductID = r.ProductID)
WHERE [Date] between @DateBegin and @DateAdd
GROUP BY 
    sp.ProductName, r.ProductID, r.QtyinPieces
HAVING
    CAST( (CAST ( SUM(sp.QtySold) AS FLOAT) / CAST(SUM(r.QtyinPieces) AS FLOAT) ) * 100 AS DECIMAL(8,2) ) > 50
ORDER BY 
    SUM(sp.QtySold) DESC

先生，你还在吗？我想补充一个问题。是的，我在这里，问题是什么？像这样写
选择TOP（@TOP）
再次感谢您，先生。我已先将该项目转换为int，并与（@top）一起使用。非常感谢。先生，你还在吗？我想补充一个问题。是的，我在这里，问题是什么？像这样写
选择TOP（@TOP）
再次感谢您，先生。我已先将该项目转换为int，并与（@top）一起使用。非常感谢。