Both the standard valued and searched CASE expressions are supported. In both cases, the ELSE expression is optional and, if not specified, the expression will return NULL if no WHEN conditions evaluate to TRUE. At least one WHEN/THEN condition is required with both forms of CASE expression, and a test expression is also required with the valued form.
A CASE statement embedded within a CASE statement as a THEN or ELSE expression is automatically enclosed in parentheses if it is not already so enclosed. This makes it easier to achieve correct syntax if a nested CASE statements is needed.
Double-click on Case to show all of the available functions and operators.
Teradata Database
The following figure shows the Case functions available when connected to a Teradata database.
Variable Creation > Input > Variables: SQL Elements pane - Case (Teradata)
Aster Database
The following figure shows the Case functions available when connected to an Aster database.
Variable Creation > Input > Variables: SQL Elements pane - Case (Aster)
