SQL Dialects Reference/Select queries/Select without tables

Select without tables edit

Sometimes one needs to execute SQL scalar expressions without table context, i.e. make a query that would act as normal SELECT operator, evaluate given comma-separated expressions and return a table with single row and one or multiple columns (one for every individual expression). Obviously, expressions can't reference any columns from the tables, as there are none.

An example is determining the value of a mathematical function, using Oracle syntax:

SQL> select 4*atan(1) as "Arc tangent of 1 times 4" from dual;

Arc tangent of 1 times 4
------------------------
              3.14159265

Standard	?
DB2	VALUES SELECT expressions FROM sysibm.sysdummy1
Firebird	SELECT expressions FROM rdb$database
Ingres	SELECT expressions
Linter	SELECT expressions
MonetDB	SELECT expressions VALUES ("expressions")
MSSQL	SELECT expressions VALUES (expressions)
MySQL	SELECT expressions SELECT expressions FROM dual VALUES row_constructor_list
Oracle	SELECT expressions FROM dual
PostgreSQL	SELECT expressions VALUES (expressions)
SQLite	SELECT expressions VALUES ("expressions")
Virtuoso	?