Select Column value to apply a unary operator to the column value or specify NULL or an expression for the column value.

To apply a unary operator to the value you have specified in the Column value field, from the Column value pull-down menu, select the unary operator. The unary operators are the first group of pull-down menu choices. The Column value field will be replaced with the expression that results from applying the unary operator to the column value you have specified.

To specify NULL for the value in the Column value field, from the Column value pull-down menu, select NULL. The Column value field will be replaced with NULL.

To specify an expression for the value in the Column value field, from the Column value pull-down menu, select Specify expression. The Column value field will be replaced with an expression once you have specified one.