在内部联接SQL语句中选择特定列

Question

我想在我最后一次内部联接中从Name中选择一个特定列（Products）。我怎样才能做到这一点？

这是我的SQL语句：

SqlCommand cmd = new SqlCommand("SELECT * FROM CustomerDetails cd INNER JOIN CustomerProducts cp ON cp.CustomerID = cd.Id INNER JOIN Products p ON cp.ProductID = p.ProductID", conn);

到目前为止，我得到了这个，是否有可能有一列？像Name一样有二氧化碳，工业氧气，因为它们属于同一个Id？谢谢

Answer 1

SqlCommand cmd = new SqlCommand("select p.[name], cd.* FROM CustomerDetails cd Inner Join CustomerProducts cp ON cp.CustomerID = cd.Id Inner Join Products p ON cp.ProductID = p.ProductID", conn);

编辑：我同意下面的评论，不建议使用cd。*，它应该是cd.Id，cd.CustomerName ......等。

这可以让您将名称组合在一个列中：

;WITH Customers AS
(
    select cd.Id, cd.customer ... FROM CustomerDetails cd 
)

SELECT stuff(
(
    select ', ' + p.[name] FROM Customers cd Inner Join CustomerProducts cp ON cp.CustomerID = cd.Id Inner Join Products p ON cp.ProductID = p.ProductID
    FOR XML PATH('')
), 1, 2, '')
, c.Id, c.CustomerName ...
FROM Customers c

Answer 2

select p.Name, cd.ColumnA, cd.ColumnB, cd.ColumnC
FROM CustomerDetails cd 
Inner Join CustomerProducts cp ON cp.CustomerID = cd.Id 
Inner Join Products p ON cp.ProductID = p.ProductID