CODEWITHSUNDEEP
c#sqlsql-server
FPGA
FPGA

Reputation: 3855

sql null in c# and null coalescing operator

i have the following sql command

var Query = new SqlCommand(@"SELECT [file] FROM [ApplicationSettings] WHERE [id] = @id And username=@username", con);
Query.Parameters.AddWithValue("@id", fileName);
Query.Parameters.AddWithValue("@username", userName ?? //then what?! );

the userName is a string (NVARCHAR in the sql), sometimes it has a value and sometimes its set to null, so i have 2 cases

username='someUserName'
username=Null

how can i achieve this in the current syntax without if statements or any additional checking

Upvotes: 0

Views: 286

Answers (1)

Allan S. Hansen
Allan S. Hansen

Reputation: 4081

Try something like:

SELECT [file] FROM [ApplicationSettings] 
WHERE [id] = @id And username=ISNULL(@username,username)

If @username is NULL, it'll compare username to username which always will be true; and if it is not null, it'll then compare username = @username. You could also use a CASE for comparison, but I find the above syntax more clean myself.

Upvotes: 2

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