What is the difference between OUTER APPLY and inner JOIN in Sql Server?

Question

What is the difference between OUTER APPLY and inner JOIN in Sql Server?

What is the difference between OUTER APPLY and INNER JOIN in Sql Server?

I know how the LEFT/RIGHT/INNER JOIN works but I came across the OUTER APPLY i gave a read but did not understand completely, it seems to be a type of open INNER JOIN where I could make an internal subselect acting as a normal JOIN. Would that be it? Or do you have more things about?

Also How would the performance be comparing them?

1

sql-server sql-server-2012

Author: Roger Oliveira, 2015-09-21

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1 answers

score 1 · Accepted Answer

An OUTER APPLY what it will do is return to NULL the fields in which there is no match. While Inner join does not return, it only returns values where there is a match. Null values are not returned.

Without being a rule, I use a lot of Apply operators when I need to invoke a call to a function.

I hope I helped.