DBNull if statement

Question

I'm trying to execute a stored procedure and then use an if statement to check for null values and I'm coming up short. I'm a VB guy so please bear with me if I'm making a schoolboy syntax error.

objConn = new SqlConnection(strConnection); objConn.Open(); objCmd = new SqlCommand(strSQL, objConn); rsData = objCmd.ExecuteReader(); rsData.Read();  if (!(rsData["usr.ursrdaystime"].Equals(System.DBNull.Value)))         {             strLevel = rsData["usr.ursrdaystime"].ToString();          } 

Would this allow me to check whether the SQL connection is returning just a value and if so then populating my string?

I'm used to being able to just check the below to see if a value is being returned and not sure I'm doing it correctly with C#

If Not IsDBNull(rsData("usr.ursrdaystime"))

Any help would be appreciated!

Answer 1

This should work.

if (rsData["usr.ursrdaystime"] != System.DBNull.Value)) {     strLevel = rsData["usr.ursrdaystime"].ToString(); } 

also need to add using statement, like bellow:

using (var objConn = new SqlConnection(strConnection))      {         objConn.Open();         using (var objCmd = new SqlCommand(strSQL, objConn))         {            using (var rsData = objCmd.ExecuteReader())            {               while (rsData.Read())               {                  if (rsData["usr.ursrdaystime"] != System.DBNull.Value)                  {                     strLevel = rsData["usr.ursrdaystime"].ToString();                  }               }            }         }      } 

this'll automaticly dispose (close) resources outside of block { .. }.

Answer 2

The idiomatic way is to say:

if(rsData["usr.ursrdaystime"] != DBNull.Value) {     strLevel = rsData["usr.ursrdaystime"].ToString(); } 

This:

rsData = objCmd.ExecuteReader(); rsData.Read(); 

Makes it look like you're reading exactly one value. Use IDbCommand.ExecuteScalar instead.