-584 INVALID USE OF NULL OR DEFAULT

Explanation
The NULL or DEFAULT keyword is not valid as specified. One
of the following error situations occurred:

The NULL keyword was used in the USING source-table clause of the MERGE
statement, but the NULL keyword was not explicitly cast to a supported data type.

In a SET
assignment-statement statement, DEFAULT was assigned to a variable other than a
global variable.

A CREATE VARIABLE statement was used
to define a global variable as an array type. The DEFAULT constant or DEFAULT
special-register clause was specified in the CREATE VARIABLE statement. Only
DEFAULT NULL is allowed.

The DEFAULT keyword was
specified as the source value for a transition variable in a SET
assignment-statement statement that assigns values to multiple targets, and either all of
the targets were not transition variables, or all of the source values were not specified with the
DEFAULT keyword.

System action
The statement cannot be processed.

User response
Take one of the following actions:

Specify the NULL keyword within a CAST expression when using NULL within the USING VALUES clause
of the MERGE statement.

Do not assign DEFAULT to any variable other than a global variable.

In a CREATE VARIABLE statement that is used to define a global variable as an
array type, do not assign DEFAULT constant or DEFAULT
special-register to the global variable.

Do not assign DEFAULT to a
transition variable in a SET assignment-statement statement that assigns values
to multiple targets if all the targets are not transition variables, or if all the source values are
not specified as the DEFAULT keyword. Replace the single assignment statement with separate
assignment statements.

SQLSTATE

42608