Change Not Null Columns

Rohan

4y1.3kSQL

Hello everyone I have one query My table name is Auth.AspNet here multiple columns set with not null means null value not set . So how to set null value accept.how to change column not null to null

4 Replies

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Rijwan Ansari4y ago
Strings are reference types, so are already "nullable". However, for other type add ? after type like
Example
public class ApplicationUser : IdentityUser
{
    public int? CustomID { get; set; }
    public string FieldName { get; set; }
}
Nitin Sontakke4y ago
Hello,

Of course you can, here is the script which I tested for you:
create table [dbo].[SomeTable]
(
  [SomeColumn] integer not null
)
go

alter table [dbo].[SomeTable]
  alter column [SomeColumn] integer null
go

drop table [dbo].[SomeTable]
go
But please take following in the consideration:
1/ If this table is created by you, then it is fine to go ahead. If not, there must a reason why it was made not null in the first place.

2/ The database practise suggests that maximum of your columns should be not null.

3/ If you can think of, it would be much nicer to have a DEFAULT constraint applied to the column instead of making it nullable.

Hope it helps!
Sachin Singh4y ago
There are multiple ways, but the easiest one is
public class ApplicationUser : IdentityUser
{
// add or modify any property.
    public string CustomTag { get; set; }
}
Now fire command add-migration anyName
it will create a migration file. here inside aspnetusers table, modify the required columns from not null to null.
then update-database.
Amit Mohanty4y ago
Try to alter the column.
ALTER TABLE table_name ALTER COLUMN column_name NULL