create table tb (ID varchar); Code example: IDataReader reader = command.ExecuteReader("select * from tb"); Console.WriteLine((string)reader["ID"]);
While: IDataReader reader = command.ExecuteReader("select \"ID\" from tb"); Console.WriteLine((string)reader["\"ID\"]; // using reader["ID"] will cause column not exists error. And: IDataReader reader = command.ExecuteReader("select \"ID\" as \"ID\" from tb"); Console.WriteLine((string)reader["ID"]); // now works again.