Question

I’m using SQL Server. This statement lists my products per menu:

SELECT menuname, productname
FROM [web].[dbo].[tblMenus]
FULL OUTER JOIN [web].[dbo].[tblProductsRelMenus]
  ON [tblMenus].Id = [tblProductsRelMenus].MenuId
FULL OUTER JOIN [web].[dbo].[tblProducts] 
  ON [tblProductsRelMenus].ProductId = [tblProducts].ProductId
LEFT JOIN [web].[dbo].[tblOrderDetails] 
   ON ([tblProducts].Id = [tblOrderDetails].ProductId)
GROUP BY [tblProducts].ProductName

Some products don’t have menus and vice versa. I use the following to establish what has been sold of each product.

SELECT [tblProducts].ProductName, SUM([tblOrderDetails].Ammount) as amount
FROM [web].[dbo].[tblProducts] 
LEFT JOIN [web].[dbo].[tblOrderDetails] 
   ON ([tblProducts].ProductId = [tblOrderDetails].ProductId)
GROUP BY [tblProducts].ProductName

What I want to do is complement the top table with an amount column. That is, I want a table with the same number of rows as in the first table above but with an amount value if it exists, otherwise null.

I can’t figure out how to do this. Any suggestions?

Answer 1

If I am not missing anything, the second query could be simplified, then incorporated into the first query like this:

SELECT
  m.menuname,
  p.productname,
  t.amount
FROM [web].[dbo].[tblMenus] m
  FULL JOIN [web].[dbo].[tblProductsRelMenus] pm ON m.Id = pm.MenuId
  FULL JOIN [web].[dbo].[tblProducts] p ON pm.ProductId = p.ProductId
  LEFT JOIN (
    SELECT ProductId, SUM(Amount) as amount
    FROM [web].[dbo].[tblOrderDetails]
    GROUP BY ProductId
  ) t ON p.ProducId = t.ProductId