Best way to handle Datarow DBNull [duplicate]

Question

Possible Duplicate:
Best way to check if a Data Table has a null value in it

I want to know what should be the way to check DBNull for a DataTable - DataRow values.

Ex

I have a DataRow which fetches information from database from rows type like :

varchar, money, Int and so on.

What should be my (simple and sweet) approach to handle such situation.

Answer 1

Try:

foreach(DataRow row in table.Rows)
{
    object value = row["ColumnName"];
    if (value == DBNull.Value)
    {

    }
    else
    {
    }
}

Answer 2

Try this

For varchar

string val = dr["name"].ToString();

For int

int? val = dr["status"] == DBNull.Value ? (int?) null : Convert.ToInt32(dr["status"]);

Do the same for Money, Decimal as done for int replacing with respective .Net types

Answer 3

You can use an extension method like this;

public static T GetValue<T>(this OracleDataReader reader, string fieldName)
{
    T result = default(T);
    int index = reader.GetOrdinal(fieldName);

    if (reader.IsDBNull(index))
    {
        return default(T);
    }

    if (typeof(T) == typeof(string))
    {
        result = (T)Convert.ChangeType(reader.GetString(index), typeof(T));
    }

    if (typeof(T) == typeof(int))
    {
        result = (T)Convert.ChangeType(reader.GetInt32(index), typeof(T));
    }

    if (typeof(T) == typeof(DateTime))
    {
        result = (T)Convert.ChangeType(reader.GetDateTime(index), typeof(T));
    }

    if (typeof(T) == typeof(byte[]))
    {
        OracleLob blob = reader.GetOracleLob(index);
        result = (T)Convert.ChangeType(blob.Value, typeof(T));
    }

    return result;
}

And you can use like string title = reader.GetValue<string>("title")