Transfer Tables Between SQL Server Databases

This How-To shows how to allow the user to choose multiple tables and copy them from one database to another as well as tables from two different databases on two different SQL servers..

7.4 Transfer Tables Between SQL Server Databases

Users sometimes need to transfer (copy) tables between SQL Server databases This

How-To shows how to allow the user to choose multiple tables and copy them from one

database to another as well as tables from two different databases on two different SQL

servers

One of the tasks your clients have you perform for them using the Enterprise Manager is

to transfer objects, such as tables, between SQL Server databases How do you create a

dialog box that would allow the user to transfer databases between two SQL Server

databases?

Technique

Unlike the earlier How-Tos in this chapter, you will be using the SQL-DTS object model

in addition to SQL-DMO You can see the objects, properties, and methods that will be

used from SQL-DTS in Table 7.7

Table 7.7 SQL-DTS Objects That Are Used to Perform the Transfer of Tables from

One SQL Server Database to Another Object Property/Method

Package Steps.New

Step TaskName

Task CustomTask CustomTask Name

SourceDatabase

DestinationServer

DestinationUseTrustedConnection DestinationDatabase

Using the items just listed, you will create a form with options to transfer tables between two SQL databases

Steps

Open and run the VB.NET -Chapter 7 solution From the main Windows form, click on the command button with the caption How-To 7.4 You will then see a form allowing you

to pick SQL Servers on the network to transfer from and to After you have chosen these, you can then select which databases you want to transfer from and to After choosing from the database to transfer from, you are then presented with a list of tables to transfer from You can then highlight multiple tables, as shown in Figure 7.9

Figure 7.9 Transferring tables between SQL Server databases

Tip

One of the options included as a property of the CustomTask object is IncludeDependencies This option specifies whether to have DTS transfer related tables as well as the selected table(s) This could be put as an option on the form as well For this example, I have it set to True

1 Create a Windows Form Then place the controls shown in Figure 7.9, with the following properties set as in Table 7.8

Table 7.8 Label, ListBox, and Command Button Controls Property Settings

ListBox Name lstToSQLServer

2 On the form, add the code in Listing 7.18 to the Load event This will look

familiar from How-To 7.1 For an examination of the LoadSQLServers routine, check out step 4 in that How-To Different from the other How-Tos in this chapter thus far, however, is the fact that the LoadSQLServers routine is called twice: once for the lstFromSQLServer, and a second time for the lstToSQLServer

Listing 7.18 frmHowTo7_4.vb: Calling the Routine That Loads Available SQL Servers into a List Box

Private Sub frmHowTo7_4_Load(ByVal sender As System.Object,

ByVal e As System.EventArgs) Handles MyBase.Load

LoadSQLServers(Me.lstFromSQLServer)

LoadSQLServers(Me.lstToSQLServer)

End Sub

3 On the lstFromSQLServer and lstToSQLServer list boxes, add the code in Listing 7.19 to the SelectedIndexChanged event of each, as appropriate These routines call GetSQLDatabases, described in step 6 of How-To 7.1

Listing 7.19 frmHowTo7_4.vb: Populating the lstDatabases and

lstBackupDevices List Boxes

Private Sub lstFromSQLServer_SelectedIndexChanged(ByVal sender As

System.Object,

ByVal e As System.EventArgs) Handles

lstFromSQLServer.SelectedIndexChanged

GetSQLDatabases(Me.lstFromSQLServer.SelectedItem, Me.lstFromDB) End Sub

Private Sub lstToSQLServer_SelectedIndexChanged(ByVal sender As

System.Object, _

ByVal e As System.EventArgs) _

Handles lstToSQLServer.SelectedIndexChanged

GetSQLDatabases(Me.lstToSQLServer.SelectedItem, Me.lstToDB)

End Sub

4 On the lstFromTables list box, add the code in Listing 7.20 to the

SelectedIndexChanged event This routine starts off by logging onto the server that is selected in the lstFromSQLServer list box, and then creates a reference to the database that is selected in the lstFromDB list box After clearing the lstTables list box, the routine iterates through each of the tables in the database and adds the names of those that are user tables to the lstTables items

Listing 7.20 frmHowTo7_4.vb: Populating the lstDatabases and

lstBackupDevices List Boxes

Private Sub lstFromDB_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lstFromDB.SelectedIndexChanged

' Create the connection and specify the stored procedure to use

Dim odb As SQLDMO.Database

Dim otbl As SQLDMO.Table

Dim oapp As New SQLDMO.Application()

Dim osvr As New SQLDMO.SQLServer()

Try

osvr.LoginSecure = True

osvr.Connect(Me.lstFromSQLServer.SelectedItem)

odb = osvr.Databases.Item(Me.lstFromDB.SelectedItem)

Me.lstTables.Items.Clear()

For Each otbl In odb.Tables

If otbl.TypeOf = _

SQLDMO.SQLDMO_OBJECT_TYPE.SQLDMOObj_UserTable Then

Me.lstTables.Items.Add(otbl.Name)

End If

Next

Catch excpData As Exception

MessageBox.Show("Error Occurred: " & excpData.Message)

End Try

End Sub

Tip

You could really make this a flexible and powerful utility by including different objects to transfer other than just user tables Some examples could be stored procedures or views

5 On the lstTables list box, add the code in Listing 7.21 to the

SelectedIndexChanged event This routine enables the btnTransfer button

Listing 7.21 frmHowTo7_4.vb: Performing the Transfer of Tables

Private Sub lstTables_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lstTables.SelectedIndexChanged

Me.btnTransfer.Enabled = True

End Sub

6 Add the code in Listing 7.22 to the Click event of btnTransfer This routine begins

by declaring all the objects to be used, and then creates new Step and Task objects, with the type of task being specified In this case, the task is of type

DTSTransferObjectsTask Next, the various necessary properties are set on the

Task object For each of the tables to be transferred, the AddObjectForTransfer method is executed, with the name of the table being passed to the method After the name of the task is added to the step, both objects are added to their collections

in the Package object The Execute method of the Package object is then called

Listing 7.22 frmHowTo7_4.vb: Performing the Transfer of Tables

Private Sub btnTransfer_Click(ByVal sender As System.Object, _

ByVal e As System.EventArgs) Handles btnTransfer.Click

Dim oPackage As New DTS.Package()

Dim oStep As DTS.Step

Dim oTask As DTS.Task

Dim oXferObj As DTS.TransferObjectsTask

Dim intCurrTable As Integer

Try

' Create step and task

oStep = oPackage.Steps.New

oTask = oPackage.Tasks.New("DTSTransferObjectsTask")

oXferObj = oTask.CustomTask

' Configure transfer objects task

With oXferObj

Name = "XferObjTask"

SourceServer = Me.lstFromSQLServer.SelectedItem

SourceUseTrustedConnection = True

SourceDatabase = Me.lstFromDB.SelectedItem

DestinationServer = Me.lstToSQLServer.SelectedItem

DestinationUseTrustedConnection = True

DestinationDatabase = Me.lstToDB.SelectedItem

CopyAllObjects = False

IncludeDependencies = True

IncludeLogins = False

IncludeUsers = False

DropDestinationObjectsFirst = False

CopySchema = True

CopyData =

DTS.DTSTransfer_CopyDataOption.DTSTransfer_AppendData

For intCurrTable = 0 To Me.lstTables.SelectedItems.Count - 1

AddObjectForTransfer( _

Me.lstTables.SelectedItems.Item(intCurrTable), "dbo", DTS.DTSSQLObjectType.DTSSQLObj_UserTable) Next

End With

' Link step to task

oStep.TaskName = oXferObj.Name

oStep.Name = "XferObjStep"

oPackage.Steps.Add(oStep)

oPackage.Tasks.Add(oTask)

oPackage.Execute()

Catch excp As Exception

MessageBox.Show(excp.Message, "Error Occurred")

Exit Sub

End Try

MessageBox.Show("Tables Transferred")

End Sub

7 Add the code in Listing 7.23 to the Click event of btnClose

Listing 7.23 frmHowTo7_4.vb: Closing the Form

Private Sub btnClose_Click(ByVal sender As System.Object, _

ByVal e As System.EventArgs) Handles btnClose.Click Me.Close()

End Sub

How It Works

Using the Data Transformation Services API requires a bit more work than just using SQL-DMO To use SQL-DTS, you need to also have a concept of using workflow Workflow allows you to specify steps in a package and assign tasks to those steps Task objects that are not assigned to steps can be included in the package, but they will not be executed You can see an example of multiple tasks being performed by the arrows in the package in Enterprise Manager (see Figure 7.10)

Figure 7.10 This DTS package has multiple tasks that are being performed and

shows workflow

This example is simple in that it has only one step and task For more information on using workflow and DTS packages, check out SQL Server's Books On-Line, and look up

"workflow."

As you create each of the tasks, you will have to set the various properties that are

necessary to perform the tasks The source and destination servers and databases are examples of this

Comments

As mentioned, using DTS takes a bit more work to understand than DMO, but after you understand what needs to be done, there is little you can't perform using it