When would you use a CTE?

A CTE (Common Table Expression) defines a temporary result set which you can then use in a SELECT statement. It becomes a convenient way to manage complicated queries. You define Common Table Expressions using the WITH statement. You can define one or more common table expression in this fashion.

Where is CTE stored?

CTE results are not stored anywhere.... they don't produce results.... a CTE is just a definition, just like a VIEW is just a definition. Think of a CTE as being a View that only lasts for the duration of the query.

Can you index a CTE?

A CTE is a temporary, "inline" view - you cannot add an index to such a construct. If you need an index, create a regular view with the SELECT of your CTE, and make it an indexed view (by adding a clustered index to the view).

Is it better to use CTE or subquery?

Advantage of Using CTE

Instead of having to declare the same subquery in every place you need to use it, you can use CTE to define a temporary table once, then refer to it whenever you need it. CTE can be more readable: Another advantage of CTE is CTE are more readable than Subqueries.

Can I use subquery in CTE?

A CTE can reference itself, a subquery cannot. A CTE can reference other CTEs within the same WITH clause (Nest). A subquery cannot reference other subqueries. A CTE can be referenced multiple times from a calling query.


Can we use CTE in view?

A Common Table Expression, also called as CTE in short form, is a temporary named result set that you can reference within a SELECT, INSERT, UPDATE, or DELETE statement. The CTE can also be used in a View.