What is the difference between null and System.DBNull.Value?
문제
Is there any difference between null and System.DBNull.Value? If yes, what is it?
I noticed this behavior now -
while (rdr.Read())
{
if (rdr["Id"] != null) //if (rdr["Id"] != System.DBNull.Value)
{
int x = Convert.ToInt32(rdr["Id"]);
}
}
While I retrieve data from the database using a sql datareader, though there is no value returned if(rdr["Id"] != null)
returned true
and eventually threw an exception for casting a null as integer.
But, this if I use if (rdr["Id"] != System.DBNull.Value)
returns false
.
What's the difference between null and System.DBNull.Value?
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