Multiple Common Table Expressions

Kevin Feasel

2016-01-07

T-SQL

Steve Jones shows how to chain Common Table Expressions:

In this way I can more easily see in the first example I’m joining two tables/views/CTEs together. If I want to know more about the details of one of those items, I can easily look up and see the CTE at the beginning.

However when I want multiple CTEs, how does this work?

The answer is simple but powerful.  Once you’ve read up on CTEs, you start to see the power of chaining CTEs.  And then you go CTE-mad until you see the performance hit of the monster you’ve created.  Not that I’ve ever done that…nope…

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