Question about exception handling

Question

Hi The prevailing wisdom for coding try/catch statements around db connections seems to be as follows: conn = new MySqlConnection(); cmdGetDate = new MySqlCommand(); try { conn.ConnectionString = connStringSQL; conn.Open(); ...do some stuff } catch (Exception dbErr) { throw new Exception(dbErr.Message); } finally { conn.Close(); cmdGetDate.Dispose(); conn.Dispose(); } My question is what if an exception occurs on closing the connection (which is inside the finally part of the try/catch)?

Dave · Answer

As I understand it using is just syntactic sugar for the block that I set out above. So the connection does get closed and disposed but in a finally block. So the same query applies. Also the 'behind-the-scenes' try/catch stuff in a using block does not actually let you catch any exceptions that are thrown. You need to nest it in an external try/catch: try{ using{} } catch{} The cost of this being the overhead of 2 try/catch statements. (Pretend in my example above that I did not throw a new exception but handled the one that was thrown). Let me know if I have this wrong.

Scott Lysle · Answer

You can use Using in the declaration of the connection; when this goes of scope or fails it will dispose of the connection. using ( SqlConnection conn = new SqlConnection (ConnString)) { conn.Open(); .... }