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VB.NET ForeignKeyConstraint類代碼示例

本文整理匯總了VB.NET中System.Data.ForeignKeyConstraint的典型用法代碼示例。如果您正苦於以下問題:VB.NET ForeignKeyConstraint類的具體用法?VB.NET ForeignKeyConstraint怎麽用?VB.NET ForeignKeyConstraint使用的例子?那麽, 這裏精選的類代碼示例或許可以為您提供幫助。


在下文中一共展示了ForeignKeyConstraint類的1個代碼示例,這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚,您的評價將有助於係統推薦出更棒的VB.NET代碼示例。

示例1: CreateConstraint

' The next line goes into the Declarations section of the module:
' SuppliersProducts is a class derived from DataSet.
Private suppliersProducts As SuppliersProducts

Private Sub CreateConstraint()
    ' Declare parent column and child column variables.
    Dim parentColumn As DataColumn
    Dim childColumn As DataColumn
    Dim fkeyConstraint As ForeignKeyConstraint

    ' Set parent and child column variables.
    parentColumn = suppliersProducts.Tables("Suppliers").Columns("SupplierID")
    childColumn = suppliersProducts.Tables("Products").Columns("SupplierID")
    fkeyConstraint = New ForeignKeyConstraint( _
        "SupplierFKConstraint", parentColumn, childColumn)

    ' Set null values when a value is deleted.
    fkeyConstraint.DeleteRule = Rule.SetNull
    fkeyConstraint.UpdateRule = Rule.Cascade
    fkeyConstraint.AcceptRejectRule = AcceptRejectRule.Cascade

    ' Add the constraint, and set EnforceConstraints to true.
    suppliersProducts.Tables("Products").Constraints.Add(fkeyConstraint)
    suppliersProducts.EnforceConstraints = True
End Sub
開發者ID:VB.NET開發者,項目名稱:System.Data,代碼行數:25,代碼來源:ForeignKeyConstraint


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