DUAL table

Any unqualified reference to the table with the name DUAL is resolved as a built-in view that returns one row and one column. The name of the column is DUMMY and its value is 'X'. The DUAL table is similar to the SYSIBM.SYSDUMMY1 table. This capability does not apply to the Entry plan of the Db2® Warehouse on Cloud managed service.

Unqualified table references to the DUAL table are resolved as SYSIBM.DUAL.

If a user-defined table named DUAL exists, the table reference is resolved to the user-defined table.

Example 1

Generate a random number by selecting from DUAL.

   SELECT RAND() AS RANDOM_NUMBER FROM DUAL

Example 2

Retrieve the value of the CURRENT SCHEMA special register.

   SET SCHEMA = MYSCHEMA;
   SELECT CURRENT SCHEMA AS CURRENT_SCHEMA FROM DUAL;