C# - Re-using a DataAdapter

Hi guys 'n gals,

I wanted to know if there is a way so consolidate my code, by maybe re-using my DataAdapter variable, rather than creating a new one for each query to the database? Here is how my code looks at the moment:

        void FillDataTables()
        {
            MySqlConnection conn = new MySqlConnection(connString);
            DataSet ds = new DataSet();
            conn.Open();
            MySqlDataAdapter adapter = new MySqlDataAdapter("SELECT * FROM tblConnections", conn);
            adapter.Fill(ds);
            adapter = null;
            MySqlDataAdapter adapter = new MySqlDataAdapter("SELECT * FROM tblInspector", conn);
            adapter.Fill(ds);
            conn.Close();

            MessageBox.Show(ds.Tables.Count.ToString());
        }


It throws the following error:

Error      1      A local variable named 'adapter' is already defined in this scope



Any ideas on getting past this?


Cheers guys!
LVL 4
Cyber-DrugsAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Jens FiedererTest Developer/ValidatorCommented:
For the second use, do
    adapter = new MySqlDataAdapter("SELECT * FROM tblInspector", conn);

You don't need (and are not allowed!) to declare it twice!
0
aponcealbuerneCommented:
hi:
Well the error is because you have the same declaration two times
MySqlDataAdapter adapter --> this is twice in the code so you can use something like:

void FillDataTables()
        {
            MySqlConnection conn = new MySqlConnection(connString);
            DataSet ds = new DataSet();
            conn.Open();
            MySqlDataAdapter adapter = new MySqlDataAdapter("SELECT * FROM tblConnections", conn);
            adapter.Fill(ds);
            adapter = null;
            adapter = new MySqlDataAdapter("SELECT * FROM tblInspector", conn);
            adapter.Fill(ds);
            conn.Close();
            MessageBox.Show(ds.Tables.Count.ToString());
        }
you can also just change the CommandText for the DataAdapter instead of recreate the object.


something like:

void FillDataTables()
        {
            MySqlConnection conn = new MySqlConnection(connString);
            DataSet ds = new DataSet();
            conn.Open();
            MySqlDataAdapter adapter = new MySqlDataAdapter("SELECT * FROM tblConnections", conn);
            adapter.Fill(ds);
            adapter = null;
            adapter.SelectComand =      "SELECT * FROM tblInspector";
            adapter.Fill(ds);
            conn.Close();
            MessageBox.Show(ds.Tables.Count.ToString());
        }


Hope helps
0
zajda82Commented:
you cant declare two variables of same name in one scope, you set your adapter to null, but variable still exists, try something like this:

using (MySqlConnection conn = new MySqlConnection("connstring"))
using (MySqlDataAdapter adapter = new MySqlDataAdapter("SELECT * FROM tblConnections", conn))
{
       conn.Open();
       adapter.Fill(ds);
       adapter.SelectCommand.CommandText = "SELECT * FROM tblInspector";
       adapter.Fill(ds);
       conn.Close();
}
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Cyber-DrugsAuthor Commented:
Thanks guys, all the solutions seem to work, although I think I will be going with zajda82's, as it allows me to just change the select statement for the adapter, rather than re-calling the while lot again.


Cheers!
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
C#

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.