將數據載入數據集

您必須先將 DataSet 物件填滿資料，才能使用 LINQ to DataSet 來對物件進行查詢。 有數種不同的方式可以填入 DataSet。 例如，您可以使用 LINQ to SQL 查詢資料庫，並將結果載入 至 DataSet。 如需詳細資訊，請參閱 LINQ to SQL。

將數據載入 至 DataSet 的另一個常見方式是使用 類別 DataAdapter 從資料庫擷取數據。 下列範例會加以說明。

範例

此範例會使用 DataAdapter 查詢 AdventureWorks 資料庫，以取得 2002 年的銷售資訊，並將結果載入 。DataSet DataSet填充後，您可以使用 LINQ to DataSet 來撰寫查詢。 FillDataSet此範例中的 方法會用於 LINQ to DataSet 範例中的範例查詢。 如需詳細資訊，請參閱 查詢數據集。

Try
    Dim connectionString As String

    connectionString = "..."

    ' Create a new adapter and give it a query to fetch sales order, contact,
    ' address, and product information for sales in the year 2002. Point connection
    ' information to the configuration setting "AdventureWorks".
    Dim da = New SqlDataAdapter( _
    "SELECT SalesOrderID, ContactID, OrderDate, OnlineOrderFlag, " & _
        "TotalDue, SalesOrderNumber, Status, ShipToAddressID, BillToAddressID " & _
        "FROM Sales.SalesOrderHeader " & _
        "WHERE DATEPART(YEAR, OrderDate) = @year; " & _
        "SELECT d.SalesOrderID, d.SalesOrderDetailID, d.OrderQty, " & _
        "d.ProductID, d.UnitPrice " & _
        "FROM Sales.SalesOrderDetail d " & _
        "INNER JOIN Sales.SalesOrderHeader h " & _
        "ON d.SalesOrderID = h.SalesOrderID  " & _
        "WHERE DATEPART(YEAR, OrderDate) = @year; " & _
        "SELECT p.ProductID, p.Name, p.ProductNumber, p.MakeFlag, " & _
        "p.Color, p.ListPrice, p.Size, p.Class, p.Style  " & _
        "FROM Production.Product p; " & _
        "SELECT DISTINCT a.AddressID, a.AddressLine1, a.AddressLine2, " & _
        "a.City, a.StateProvinceID, a.PostalCode " & _
        "FROM Person.Address a " & _
        "INNER JOIN Sales.SalesOrderHeader h " & _
        "ON  a.AddressID = h.ShipToAddressID OR a.AddressID = h.BillToAddressID " & _
        "WHERE DATEPART(YEAR, OrderDate) = @year; " & _
        "SELECT DISTINCT c.ContactID, c.Title, c.FirstName, " & _
        "c.LastName, c.EmailAddress, c.Phone " & _
        "FROM Person.Contact c " & _
        "INNER JOIN Sales.SalesOrderHeader h " & _
        "ON c.ContactID = h.ContactID " & _
        "WHERE DATEPART(YEAR, OrderDate) = @year;", _
    connectionString)

    ' Add table mappings.
    da.SelectCommand.Parameters.AddWithValue("@year", 2002)
    da.TableMappings.Add("Table", "SalesOrderHeader")
    da.TableMappings.Add("Table1", "SalesOrderDetail")
    da.TableMappings.Add("Table2", "Product")
    da.TableMappings.Add("Table3", "Address")
    da.TableMappings.Add("Table4", "Contact")

    da.Fill(ds)

    ' Add data relations.
    Dim orderHeader As DataTable = ds.Tables("SalesOrderHeader")
    Dim orderDetail As DataTable = ds.Tables("SalesOrderDetail")
    Dim co As DataRelation = New DataRelation("SalesOrderHeaderDetail", _
                                    orderHeader.Columns("SalesOrderID"), _
                                    orderDetail.Columns("SalesOrderID"), True)
    ds.Relations.Add(co)

    Dim contact As DataTable = ds.Tables("Contact")
    Dim orderContact As DataRelation = New DataRelation("SalesOrderContact", _
                                    contact.Columns("ContactID"), _
                                    orderHeader.Columns("ContactID"), True)
    ds.Relations.Add(orderContact)
Catch ex As SqlException
    Console.WriteLine("SQL exception occurred: " & ex.Message)
End Try

另請參閱

• LINQ to DataSet 概觀
• 查詢數據集
• LINQ to DataSet 範例