datasets.vb

来自「东软内部材料（六）ado .net相关」· VB 代码 · 共 352 行 · 第 1/2 页

        'daCustomers
        '
        Me.daCustomers.SelectCommand = Me.cmdSelectCustomers
        Me.daCustomers.TableMappings.AddRange(New System.Data.Common.DataTableMapping() {New System.Data.Common.DataTableMapping("Table", "CustomerList", New System.Data.Common.DataColumnMapping() {New System.Data.Common.DataColumnMapping("CustomerID", "CustomerID"), New System.Data.Common.DataColumnMapping("CompanyName", "CompanyName"), New System.Data.Common.DataColumnMapping("City", "City"), New System.Data.Common.DataColumnMapping("Country", "Country"), New System.Data.Common.DataColumnMapping("PostalCode", "PostalCode"), New System.Data.Common.DataColumnMapping("Region", "Region")})})
        '
        'btnTable
        '
        Me.btnTable.Location = New System.Drawing.Point(416, 32)
        Me.btnTable.Name = "btnTable"
        Me.btnTable.Size = New System.Drawing.Size(96, 23)
        Me.btnTable.TabIndex = 4
        Me.btnTable.Text = "CreateTable"
        '
        'btnRelation
        '
        Me.btnRelation.Location = New System.Drawing.Point(416, 64)
        Me.btnRelation.Name = "btnRelation"
        Me.btnRelation.Size = New System.Drawing.Size(96, 23)
        Me.btnRelation.TabIndex = 4
        Me.btnRelation.Text = "Create Relation"
        '
        'btnClone
        '
        Me.btnClone.Location = New System.Drawing.Point(416, 96)
        Me.btnClone.Name = "btnClone"
        Me.btnClone.Size = New System.Drawing.Size(96, 23)
        Me.btnClone.TabIndex = 4
        Me.btnClone.Text = "Clone DataSet"
        '
        'btnCopy
        '
        Me.btnCopy.Location = New System.Drawing.Point(416, 128)
        Me.btnCopy.Name = "btnCopy"
        Me.btnCopy.Size = New System.Drawing.Size(96, 23)
        Me.btnCopy.TabIndex = 4
        Me.btnCopy.Text = "Copy DataSet"
        '
        'DsMaster1
        '
        Me.DsMaster1.DataSetName = "dsMaster"
        Me.DsMaster1.Locale = New System.Globalization.CultureInfo("en-US")
        Me.DsMaster1.Namespace = "http://www.tempuri.org/dsMaster.xsd"
        '
        'dsUntyped
        '
        Me.dsUntyped.DataSetName = "dsUntyped"
        Me.dsUntyped.Locale = New System.Globalization.CultureInfo("en-US")
        Me.dsUntyped.Relations.AddRange(New System.Data.DataRelation() {New System.Data.DataRelation("MasterChild", "dtMaster", "dtChild", New String() {"MasterID"}, New String() {"MasterLink"}, False)})
        Me.dsUntyped.Tables.AddRange(New System.Data.DataTable() {Me.dtMaster, Me.dtChild})
        '
        'dtMaster
        '
        Me.dtMaster.Columns.AddRange(New System.Data.DataColumn() {Me.MasterID, Me.MasterValue})
        Me.dtMaster.Constraints.AddRange(New System.Data.Constraint() {New System.Data.UniqueConstraint("Constraint1", New String() {"MasterID"}, False)})
        Me.dtMaster.TableName = "dtMaster"
        '
        'MasterID
        '
        Me.MasterID.AllowDBNull = False
        Me.MasterID.AutoIncrement = True
        Me.MasterID.Caption = "MasterID"
        Me.MasterID.ColumnName = "MasterID"
        Me.MasterID.DataType = GetType(System.Int32)
        '
        'MasterValue
        '
        Me.MasterValue.Caption = "MasterValue"
        Me.MasterValue.ColumnName = "MasterValue"
        '
        'dtChild
        '
        Me.dtChild.Columns.AddRange(New System.Data.DataColumn() {Me.ChildID, Me.MasterLink, Me.ChildValue})
        Me.dtChild.Constraints.AddRange(New System.Data.Constraint() {New System.Data.ForeignKeyConstraint("MasterChild", "dtMaster", New String() {"MasterID"}, New String() {"MasterLink"}, System.Data.AcceptRejectRule.None, System.Data.Rule.Cascade, System.Data.Rule.Cascade)})
        Me.dtChild.TableName = "dtChild"
        '
        'ChildID
        '
        Me.ChildID.AllowDBNull = False
        Me.ChildID.AutoIncrement = True
        Me.ChildID.Caption = "ChildID"
        Me.ChildID.ColumnName = "ChildID"
        Me.ChildID.DataType = GetType(System.Int32)
        '
        'MasterLink
        '
        Me.MasterLink.AllowDBNull = False
        Me.MasterLink.Caption = "MasterLink"
        Me.MasterLink.ColumnName = "MasterLink"
        Me.MasterLink.DataType = GetType(System.Int32)
        '
        'ChildValue
        '
        Me.ChildValue.Caption = "ChildValue"
        Me.ChildValue.ColumnName = "ChildValue"
        '
        'frmDataSets
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(520, 373)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.btnCopy, Me.btnClone, Me.btnRelation, Me.btnTable, Me.dgOrders, Me.lbClients, Me.lbEmployees, Me.lblOrders, Me.lblClients, Me.lblEmployees})
        Me.Name = "frmDataSets"
        Me.Text = "DataSets"
        CType(Me.dgOrders, System.ComponentModel.ISupportInitialize).EndInit()
        CType(Me.DsMaster1, System.ComponentModel.ISupportInitialize).EndInit()
        CType(Me.dsUntyped, System.ComponentModel.ISupportInitialize).EndInit()
        CType(Me.dtMaster, System.ComponentModel.ISupportInitialize).EndInit()
        CType(Me.dtChild, System.ComponentModel.ISupportInitialize).EndInit()
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub btnTable_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnTable.Click
        Dim strMessage As String

        'Create the table
        Dim dtEmployees As System.Data.DataTable
        dtEmployees = Me.dsEmployees.Tables.Add("Employees")

        'Add the columns
        dtEmployees.Columns.Add("EmployeeID", _
            Type.GetType("System.Int32"))
        dtEmployees.Columns.Add("FirstName", _
            Type.GetType("System.String"))
        dtEmployees.Columns.Add("LastName", _
            Type.GetType("System.String"))

        'Fill the DataSet
        Me.daEmployees.Fill(Me.dsEmployees.Tables("Employees"))
        strMessage = "The first employee is "
        strMessage &= _
            Me.dsEmployees.Tables("Employees").Rows(0).Item("LastName")
        MessageBox.Show(strMessage)
    End Sub

    Private Sub btnRelation_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnRelation.Click
        Dim strMessage As String

        'Add a new relation
        Me.DsMaster1.Relations.Add("CustomerOrders", _
            Me.DsMaster1.CustomerList.CustomerIDColumn, _
            Me.DsMaster1.OrderTotals.CustomerIDColumn)

        strMessage = "The name of the DataRelation is "
        strMessage &= Me.DsMaster1.Relations(0).RelationName.ToString
        MessageBox.Show(strMessage)
    End Sub

    Private Sub btnClone_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnClone.Click
        Dim strMessage As String
        Dim dsClone As System.Data.DataSet

        dsClone = Me.DsMaster1.Clone()
        strMessage = "The cloned dataset has "
        strMessage &= dsClone.Tables.Count.ToString
        strMessage &= " Tables."
        MessageBox.Show(strMessage)
    End Sub

    Private Sub btnCopy_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnCopy.Click
        Dim strMessage As String
        Dim dsCopy As System.Data.DataSet

        'Fill the original dataset
        Me.daCustomers.Fill(Me.DsMaster1.CustomerList)

        dsCopy = Me.DsMaster1.Copy
        strMessage = "The copied dataset has "
        strMessage &= _
            dsCopy.Tables("CustomerList").Rows.Count.ToString
        strMessage &= " rows in the CustomerList."
        MessageBox.Show(strMessage)
    End Sub
End Class