Oracle missing FROM clause-CodePudding

Is it possible to create a CTE without a FROM, and if not isn't that the whole point of a CTE in the first place?

WITH cte AS
(
  SELECT 1 AS col1, 2 AS col2
)
SELECT col1, col2 FROM cte;

> ORA-00923: FROM keyword not found where expected

It seems a quick-fix for this is just adding FROM DUAL whenever needed. Is that what's supposed to be done?

CodePudding user response：

Yes, that's exactly what dual is supposed to be used for.

Selecting from the DUAL table is useful for computing a constant expression with the SELECT statement. Because DUAL has only one row, the constant is returned only once.

https://docs.oracle.com/cd/B19306_01/server.102/b14200/queries009.htm