By specifying a DEFAULT predicate ( default_predicate), you can check whether a column contains the DEFAULT value defined for this column.
<default_predicate>::= <column_spec> <comp_op> DEFAULT <comp_op>::= < | > | <> | != | = | <= | >= | ~= <! for computers with ASCII code !> | ~< <! for computers with ASCII code !> | ~> <! for computers with ASCII code !>
Explanation
A DEFAULT specification must be made for the specified column. This can be done in the following SQL statements:
If the column contains the NULL value, <column_spec><comp_op> DEFAULT is undefined.
The rules for comparing values or value lists, as defined for comparison predicates, apply here.