CODEWITHSUNDEEP
.netsqldatabaseado.net
Cyril Gupta
Cyril Gupta

Reputation: 13723

How can I check for DBNull while executing my command only once?

When I retrieve any Scalar value from the database, I usually write code like this for nullable fields.

cmd.ExecuteScalar() == DBNull.Value ? 0 : (int)cmd.ExecuteScalar()

But I don't like it because it executes the Executescalar statement twice. It's an extra trip to the server for my website and in favor of performance I don't want to do this.

Is there any way I can get rid of this extra ExecuteScalar()?

Upvotes: 7

Views: 5238

Answers (3)

askheaves
askheaves

Reputation: 755

Write yourself an extension method for the sql command.

public static T ExecuteNullableScalar<T>(this SqlCommand cmd)
    where T : struct
{
    var result = cmd.ExecuteScalar();
    if (result == DBNull.Value) return default(T);
    return (T)result;
}

Usage becomes:

int value = cmd.ExecuteNullableScalar<int>();

Upvotes: 17

Charles Bretana
Charles Bretana

Reputation: 146499

 object o = cmd.ExecuteScalar();
 return (o== DBNull.Value) ? 0 : (int)o;

Upvotes: 4

Matt Hamilton
Matt Hamilton

Reputation: 204219

Just use a variable to cache the result:

var o = cmd.ExecuteScalar();
return o == DBNull.Value ? 0 : (int)o;

Upvotes: 12

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