Are All The Database Open/Close Necessary?

Question

I feel this is a bit overkill opening/closing the connection so many times.  Their must be a way to simplify this but I am to much of a novice to know how, can a more experienced one assist?
public static void DeleteCreateWrite()
OleDbConnection oleconn = new OleDbConnection(AccessConnectionString);
oleconn.Open();
try
string[] tablename = new string[1] { "tbl_Data", };
for (int q = tablename.GetLowerBound(0); q <= tablename.GetUpperBound(0); q++)
OleDbCommand cmd = new OleDbCommand("DROP TABLE " + tablename[q], oleconn);
try { cmd.ExecuteNonQuery(); }
catch { }
catch { }
oleconn.Close();
OleDbConnection olc = new OleDbConnection(AccessConnectionString);
olc.Open();
try
OleDbCommand command = new OleDbCommand();
try
command.Connection = olc;
command.CommandText = CreateTableSQL;
command.CommandType = CommandType.Text;
try { command.ExecuteNonQuery(); }
catch { }
command.Dispose();
catch { }
catch { }
olc.Close();
OleDbConnection con1 = new OleDbConnection(AccessConnectionString);
con1.Open();
try
OleDbCommand cm = new OleDbCommand();
cm.CommandText = "Insert Into " + AccessTableName + "([C], [E], [R]) VALUES (@C, @E, @R)";
cm.Parameters.AddWithValue("@C", field1);
cm.Parameters.AddWithValue("@E", PgName);
cm.Parameters.AddWithValue("@R", field2);
cm.CommandType = CommandType.Text;
cm.Connection = con1;
try { cm.ExecuteNonQuery(); }
catch { }
catch { }
con1.Close();

Answer 1

try-finally is a lot of code if the object is disposable.
//Your code isn't exception safe. You are silently ignoring exceptions but your late code blocks assume
//that it doesn't (i.e. a drop fails but you try to create anyway)
public static void DeleteCreateWrite ()
using (var oleconn = new OleDbConnection(AccessConnectionString))
oleconn.Open();
var tablename = new string[] { "tbl_Data", };
//This is inefficient, combine all the drops into a single batch statement
for (int q = 0; q <= tablename.Length; q++)
using (var cmd = new OleDbCommand("DROP TABLE " + tablename[q], oleconn))
cmd.ExecuteNonQueryIgnoringErrors();
using (var command = new OleDbCommand())
command.Connection = oleconn;
command.CommandText = CreateTableSQL;
command.CommandType = CommandType.Text;
command.ExecuteNonQueryIgnoringErrors();
using (var cm = new OleDbCommand())
cm.CommandText = "Insert Into " + AccessTableName + "([C], [E], [R]) VALUES (@C, @E, @R)";
cm.Parameters.AddWithValue("@C", field1);
cm.Parameters.AddWithValue("@E", PgName);
cm.Parameters.AddWithValue("@R", field2);
cm.CommandType = CommandType.Text;
cm.Connection = oleconn;
cm.ExecuteNonQueryIgnoringErrors();
And the helper method that I don't agree with but mimics your existing code.
static class CommandExtensions
public static void ExecuteNonQueryIgnoringErrors ( this IDbCommand command )
try
command.ExecuteNonQuery();
} catch
/* This is bad since some exceptions aren't recoverable... */
Michael Taylor
http://blogs.msmvps.com/p3net