Setting a field or variable to NULL
Fields and variables can be set to NULL using
the same syntax as for regular values:
insert into MyTable values (1, 'teststring', NULL, '8-May-2004')
update MyTable set MyField = null where YourField = -1
if (Number = 0) then MyVariable = null;
- “Wait a minute... and you said that MyField =
NULL was illegal!”
That's right... for the comparison operator
“=” (at least in pre-2.0 versions of
Firebird). But here we are talking about
“=” as an assignment
operator. Unfortunately, both operators have the same symbol in
SQL. In assignments, whether done with “=”
or with an insert list, you can treat NULL just like
any value - no special syntax needed (or indeed possible).
