Menu
I recently learned about CTE's in SQL Server and am attempting to use it in PL/SQL. I do not need the recurive benefits of it, however, I would like to use it in lieu of creating a view and to improve query performance. Just looking for some direction on what code may be similar.
342
The Common Table Expression or CTE SQL feature is available in the following databases: Oracle (as of version 9.2) SQL Server (as of version 2005) MySQL (as of version 8.0)
CTE ORACLE is a simple query to simplify the different classes of SQL queries as the derived table concept was just not suitable can be defined as a named temporary result set which can only exist within the scope of a single statement (In this case statement here means SELECT and also DML statements like INSERT and ...
A common table expression (CTE) is a named temporary result set that exists within the scope of a single statement and that can be referred to later within that statement, possibly multiple times.
In Oracle this is known as subquery factoring, and it works the same as in SQL Server AFAIK:
with cte as (select * from emp)
select * from cte join dept on dept.deptno = cte.deptno;
See SELECT documentation and search for "factoring".
56
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
