How to Insert Null Value in A Sql Date/Time Field?

Answer 1

Make that column allows null values, then enter .
But U better use an old value instead of NULL. A value like 01/01/1900

Answer 2

use the keyword NULL

eg

insert mytable
values (this, that, NULL, somethingelse)

Edit:
of course, i am assuming the column allows nulls - if it has a not null constraint then you can't insert a null

Answer 3

use not null property in to your database and insert null using

INSERT INTO databasename VALUES('one','two',0,'three')