Comments on: SQL SERVER – Explanation and Understanding NOT NULL Constraint http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/ Personal Notes of Pinal Dave Sun, 12 Feb 2012 09:22:39 +0000 hourly 1 http://wordpress.com/ By: Mayur http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-249979 Wed, 08 Feb 2012 12:34:02 +0000 http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-249979 when i write
create table accounts(accno int identity(1001,1) primary key,accnm varchar(50) not null,acctype char(8) default ‘Saving’, city varchar(50) default ‘amravati’,balance float check(balance>=500),atmno int unique),\
here accnnm take null value n creates the table.
Is there any other way to define not null value?

]]> By: SQL SERVER – Interview Questions and Answers – Frequently Asked Questions – Day 9 of 31 Journey to SQLAuthority http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-147032 Sat, 09 Jul 2011 01:31:46 +0000 http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-147032 [...] (Read more here) [...]

]]> By: robert http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-104459 Thu, 09 Dec 2010 14:55:35 +0000 http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-104459 hi pinal,
all your posts and articles are very helpful. Thanks

]]> By: Pinku raj http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-82456 Sat, 31 Jul 2010 10:46:59 +0000 http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-82456 Hello Pinal,

Is there any problem If I change the Not NULL Constraint to NULL Constraint in a Existance Table.

I have a Table which has a large Amount of data which has a Specific Column and whose Constraint is Not Null But for some reason I have to change that constraint to NULL.

So, Is there will be any Problem If I change the Not Null Constraint to Null Constraint in a Existance Column of a Table

With Regards,
Pinku Raj

]]> By: Jawad http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-81254 Thu, 22 Jul 2010 13:27:07 +0000 http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-81254 its not possible in sql server as far as i know.

]]> By: Frank Picone http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-58632 Mon, 14 Dec 2009 23:01:42 +0000 http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-58632 Hello Pinal,

Well, I confess, I rarely ask experts for assitance, prefering to muddle through and work out a problem. However, I cannot figure out if I am walking repeatedly into a brick wall on this problem.

Is it possible to add a NAMED not null constraint to a column (presuming only non-null entries in the column at the time of constraint creation)?

I’ve seen the syntax for adding a non-named constraint and a named constraint at time of table creation or column addition, but I cannot find even a reference for creation of a NAMED not-null constraint after column creation.

Thank you very much for your time,
Frank

]]> By: Sudhakar M http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-54414 Tue, 04 Aug 2009 11:17:58 +0000 http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-54414 How to drop system generated not null constraints in Sql server

]]> By: SQL SERVER - 2008 - Interview Questions and Answers - Part 4 Journey to SQL Authority with Pinal Dave http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-47469 Thu, 26 Feb 2009 12:02:53 +0000 http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-47469 [...] (Read More Here) [...]

]]> By: jeet http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-43859 Wed, 22 Oct 2008 11:53:52 +0000 http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-43859 ho do i disable null constraint for a time being?

]]> By: Jyothi P http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-42866 Tue, 16 Sep 2008 20:29:13 +0000 http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-42866 Nikhil,

If you have created a table like this

create table Emp (Ename varchar(10) not null)

You can alter the Table ..

alter table Emp alter column Ename varchar(10) null

]]> By: DileepReddy Namburu http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-35091 Tue, 15 Apr 2008 12:42:33 +0000 http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-35091 Hi , pinal..it was a nice journey watching ur website….

]]> By: nikhil http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-34845 Fri, 04 Apr 2008 11:12:23 +0000 http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-34845 how to drop not null constraint

]]> By: Raj http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-34785 Wed, 02 Apr 2008 09:03:00 +0000 http://blog.sqlauthority.com/2007/10/15/sql-server-explanation-and-understanding-not-null-constraint/#comment-34785 The only problem with

ALTER TABLE ConstraintTable
ALTER COLUMN ID INT NOT NULL

is that if there is an index / constraint on this column then the statement fails with

Msg 5074, Level 16, State 1, Line 1
The index ‘BLAH’ is dependent on column ‘BLAH’.
Msg 4922, Level 16, State 9, Line 1
ALTER TABLE ALTER COLUMN BLAH failed because one or more objects access this column.

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