Question

These scripts give me the same result

SELECT * FROM
(select x = null) x
OUTER APPLY
(select x = 1) y  

SELECT * FROM
(select x = null) x
CROSS APPLY
(select x = 1) y

Are CROSS APPLY and OUTER APPLY the same?

Is there an example of a situation where they do not return the same result?

Answer 1

Think INNER JOIN (for CROSS) and LEFT JOIN (for OUTER) to make the distinction easier to understand. CROSS returns only rows from the outer table where the applied function returns a result set. OUTER returns all rows from the outer table.