Handling Null in C# win application

[andyehi]

Hi
My application will select and read records using datareader from mysql table and do insert or update on access data base.My problem is when I set the mdb database to allow zero length string the code below works fine.But if it is set to no.I get this error.I want to however insert a null in Access database.Any help would be great! Thanks

// Field 'patientinfo.Pa tient Last' cannot be a zero-length string. //

 

 string firstname1 = myreader["firstname"].ToString();

  string lastname1 = myreader["lastname"].ToString();

  string CI_address11 = myreader["CI_address1"].ToString();

  string CI_address21 = myreader["CI_address2"].ToString();

// insert query 

 OdbcCommand mycommand4 = new OdbcCommand("insert into patientinfo([patientid],[patient first],[patient last],[pt DOB],[SSN],[address],[address2],[city],[state],[zipcode],[sex]) values ('" + MRN1 + "','" + firstname1 + "','" + lastname1 + "','" + dob1 + "','" + ssn1 + "','" + CI_address11 + "','" + CI_address21 + "','" + CI_city1 + "','" + CI_state1 + "','" + CI_zip1 + "','" + sex1 + "')", mdbconn);
  
 int k = mycommand4.ExecuteNonQuery();

[Plater]

Take a look at DBNull.Value

[andyehi]

Thank you ,will try it.