Question

Can anyone please suggest me whether this code will cause concurrency or not.

This is a static class used in forms and and used for some database transactions.

This involves invoking of static function from asp.net pages and passing parameters as ref type.

I am using reference type.

As it is web based,does it Create some concurrency.
///

Here is code from my sample class.

public static class DataClass
{

  static SqlConnection con = new SqlConnection(
      ConfigurationManager.ConnectionStrings["sqlserverconnectionstring"]
                                                .ConnectionString);

    public static string  GetCon()

    {

     return ConfigurationManager.ConnectionStrings["sqlserverconnectionstring"].ConnectionString;

    }
    public static void Conn(ref SqlConnection con)
    {
        if (con.State == ConnectionState.Closed)
        {
            con.Open();
        }
    }
    public static DataSet GetDataSet(string qry)
    {
        SqlDataAdapter adp = new SqlDataAdapter(qry, con);
        DataSet ds = new DataSet();
        adp.Fill(ds);
        return ds;
    }
    public static bool ExecuteCommand(ref SqlCommand cmd)
    {
        bool i =true;
        cmd.Connection = con;
        Conn(ref con);
        SqlTransaction trans =con.BeginTransaction(); 
        cmd.Transaction = trans;
        try
        {
            cmd.ExecuteNonQuery();
            trans.Commit();
        }
        catch
        {
            trans.Rollback();
            i = false;
        }
        finally
        {
            cmd.Dispose();
            con.Close(); 
        }
        return i;
    }
}

Answer 1

Since you have defined a static SQLConnection, I believe it may cause concurrency issues.

static SqlConnection con = new SqlConnection (ConfigurationManager.ConnectionStrings["sqlserverconnectionstring"].ConnectionString);

If two different objects try to run a query, they will run them on the same instance of sql connection object.