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POMultiple Database connections within 1 application - VB .NET
 

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  1. POMultiple Database connections within 1 application - VB .NET
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    <p>This may have been answered but my search hasn't found what I was looking for.</p> <p>Basically, I am developing an application which allows the user to build a query at design time, i.e. for users with no prerequisite knowledge of SQL</p> <p>The application thus far allows the user to select which table(s) from the database they wish to start querying (I won't go into the details of the rest for now)</p> <p>My confusion is this; I already have the connection to the database in a subroutine which obtains the schema information and filters it to display only the available tables within the database, which then compiles the data into a listbox, here is that sub:</p> <pre><code> Public Sub getSchemaInfo() Dim ds As New DataSet Dim dt As New DataTable Dim con As New OleDbConnection Dim strDatabaseLocation As String = Application.StartupPath Dim da As New OleDbDataAdapter Dim i As Integer 'ds.Tables.Add(dt) con.ConnectionString = "Provider=microsoft.jet.oledb.4.0; data source = " &amp; strDatabaseLocation &amp; _ "\EmployeeDepartment.mdb" 'clear listbox of any data first frmAddTable.lbTables.Items.Clear() 'Try catch block used to handle connection errors gracefully Try con.Open() 'Accessing methods to obtain schema information dt = con.GetOleDbSchemaTable(OleDb.OleDbSchemaGuid.Tables, New Object() _ {Nothing, Nothing, Nothing, "TABLE"}) 'loop datatable to store schema information within it For i = 0 To dt.Rows.Count - 1 'compile lbtables with a list of available tables from the database frmAddTable.lbTables.Items.Add(dt.Rows(i)!TABLE_NAME.ToString()) Next Catch ex As Exception MessageBox.Show(ex.Message.ToString(), "Data Load Error", MessageBoxButtons.OK, MessageBoxIcon.Exclamation) End Try con.Close() </code></pre> <p>As you can see, at the very top is all the information regarding the connection to the database and loading of the information into the dataset.</p> <p>My question is this; Whenever I need to gain access to the database and any information within it, will I have to perform all the connection process (oledbconnection, etc..) or is there I way I can create a class for the connection functions and simply reference them whenever I need to connect?</p> <p>For example, I now am in the process of creating another sub which gathers the columns, based on the tables chosen in the listbox, and displays it back onto the main form in the relevant checklistbox, again, connecting to the database, therefore would I need to perform all of the connection processes?</p> <p>Any information would be very useful, thank you!</p>
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    1. COAfter reading more, would this be suited to something referred to as "Connection Pooling"? If so, could anyone elaborate perhaps?
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