Question

As an example:

SELECT name, address, phone FROM USER; 

Generates the table

name | address | phone  ...  |   ...   |  ... 

How can i use this table generated to make another query to it?

For example:

SELECT count(address) FROM (SELECT name, address, phone, from user); 

I know it’s not the best example, but is there any way to do this?

Answer 1

Use the same syntax but give your derived table an alias

SELECT count(subadd.address)  FROM (SELECT name, address, phone, from user) as subadd;