选择内部联接SQL语句中的特定列

Question

我想从我上一个内部联接的“ Products选择特定的列（“ Name ）。 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，我已经明白了，是否可以为此提供一栏？ 像Name一样，因为它们具有相同的ID，所以含有二氧化碳，工业氧气？ 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。

这应该使您将名称归为一列：

;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