Question

I am working on a SQL Server 2008 database. I need to get a specific order for a customer and their latest order ID and latest order data. My challenge here is, I need the data in a single row. Currently, I’m trying the following query:

 SELECT
  o.*,
  c.[FirstName],
  c.[LastName],
  c.[PlayerName],
  (SELECT TOP 1 o2.CreatedDate, o2.ID  FROM [Order] o2 ORDER BY [CreatedOn] DESC)
 FROM
  [Order] o,
  [Customer] c
 WHERE  
  o.[ID]=c.[CustomerID]

When I execute this query, I get the following error:

Only one expression can be specified in the select list when the subquery is not introduced with EXISTS.

As you can imagine, there are scenarios where a customer will NOT have a previous order. How do I do this and get the result into a single row?

Thank you!

Answer 1

Slightly different way to do it using a CTE.

WITH LatestOrder AS (SELECT TOP 1 * FROM [Order] ORDER BY [CreatedOn] DESC) 
 SELECT
  o.*,
  c.[FirstName],
  c.[LastName],
  c.[PlayerName],
  lo.CreatedDate,
  lo.ID
 FROM [Order] o
 JOIN [Customer] c
    ON o.[ID]=c.[CustomerID]
 CROSS JOIN LatestOrder lo