SQL Dialects Reference/Select queries/Select without tables

From Wikibooks, open books for an open world
< SQL Dialects Reference
Jump to: navigation, search

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.

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