I am wondering if it is possible to use an SQL function to name the column of a query. As a simple example:
SELECT id AS SUBSTR('xAlias', 2) FROM foo
should theoretically return
Alias ------ ... results ...
If we can, which databases would this be available for? If not, then why?
AFAIK, there is no SQL way in any major DBMS product to support this.
To name PIVOT columns in Oracle,
for name in.. as seems like the best option.
Apart from that, it’s over to dynamic SQL.
Original answer below
To name the column of a query, the ANSI standard is simply to add the new name after the column (derived or base) prepended by “AS”:
SELECT id, field1, field2 * qty FROM foo
All columns renamed below:
SELECT id AS RenamedID, field1 AS Col1, field2 * qty AS ExtendedTotal FROM foo
This standard works for pretty much all major database systems.
There are some vendor specific variations, such as SQL Server allowing the equal sign
SELECT RenamedID=id FROM foo
And most DBMS allow the omission of the “AS” keyword
SELECT id RenamedID FROM foo