Contains Query on multiple columns

Question

How do I search multiple columns using LINQ to SQL when any one of the column could be null?

IEnumerable<User> users = from user in databaseUsers
        where
             user.ScreenName.Contains(search)
             || user.FirstName.Contains(search)
             || user.LastName.Contains(search)
        select user;

I keep getting this exception:

Object reference not set to an instance of an object.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

score 8 · Accepted Answer · answered Apr 22 '11 at 16:08

8

add not null condition user.Property != null

  IEnumerable<User> users = from user in databaseUsers
    where
         (user.ScreenName != null && user.ScreenName.Contains(search))
         || (user.FirstName != null && user.FirstName.Contains(search))
         || ( user.LastName != null && user.LastName.Contains(search))
    select user;

answered Apr 22 '11 at 16:08

Andrei Andrushkevich

9,905
4
31
42

the null error was caused by the either the ScreenName, FirstName or the LastName being null. Putting in user.ScreenName != null and surrounding it and the Contains filter with brackets ( ) did the trick. Thanks. – LaundroMatt Apr 24 '11 at 05:23

score 2 · Answer 2 · answered Sep 28 '12 at 22:25

2

IEnumerable<User> users = from user in databaseUsers
where
     (user.ScreenName + ' ' + user.FirstName + ' ' + user.LastName).Contains(search)
select user;

answered Sep 28 '12 at 22:25

lfnaves

29
2

score 0 · Answer 3 · answered Apr 22 '11 at 16:08

0

Either your user is a null entry, or your databaseUsers are not initialized.

answered Apr 22 '11 at 16:08

Jake Kalstad

2,045
14
20

Contains Query on multiple columns

3 Answers3

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