Object cannot be cast from DBNull to other types.

Question

my code is private int GetNextStudentID() { command.CommandText = SELECT IDENT_CURRENT ('admn') + IDENT_INCR ('admn'); try { connection.Open(); int nextID = Convert.ToInt32(command.ExecuteScalar());// here i am getting error return nextID; } catch (SqlException ex) { MessageBox.Show(ex.Message); } finally { connection.Close(); } return 0; }

Ravi Patel · Answer

Hi try this private int GetNextStudentID() { command.CommandText = SELECT IDENT_CURRENT ('admn') + IDENT_INCR ('admn'); try { connection.Open(); var nextID = command.ExecuteScalar(); if(!(nextID is DBNull)) { nextID = Convert.ToInt32(nextID); } return nextID; } catch (SqlException ex) { MessageBox.Show(ex.Message); } finally { connection.Close(); } return 0; }

raju m · Answer

Thank you for responding I tried your code but private int GetNextStudentID() { command.CommandText = SELECT IDENT_CURRENT ('admn') + IDENT_INCR ('admn'); try { connection.Open(); var nextID = command.ExecuteScalar(); if(!(nextID is DBNull)) { nextID = Convert.ToInt32(nextID); } return nextID ; // here i an getting error like this } catch (SqlException ex) { MessageBox.Show(ex.Message); } finally { connection.Close(); } return 0; }