ColumnAttribute.Expression 屬性

public:
 property System::String ^ Expression { System::String ^ get(); void set(System::String ^ value); };

public string Expression { get; set; }

member this.Expression : string with get, set

Public Property Expression As String

屬性值

預設 = 空。

範例

[Column(Storage="_UnitPrice", DbType="Money",Expression="UnitPrice + 1.00")]
public System.Nullable<decimal> UnitPrice
{
    get
    {
        return this._UnitPrice;
    }
    set
    {
        if ((this._UnitPrice != value))
        {
            this.OnUnitPriceChanging(value);
            this.SendPropertyChanging();
            this._UnitPrice = value;
            this.SendPropertyChanged("UnitPrice");
            this.OnUnitPriceChanged();
        }
    }
}

   <Column(Storage:="_UnitPrice", DbType:="Money NOT NULL", Expression:="UnitPrice + 1.00")> _
Public Property UnitPrice() As Decimal
       Get
           Return Me._UnitPrice
       End Get
       Set(ByVal value As Decimal)
           If ((Me._UnitPrice = Value) _
              = False) Then
               Me.OnUnitPriceChanging(Value)
               Me.SendPropertyChanging()
               Me._UnitPrice = Value
               Me.SendPropertyChanged("UnitPrice")
               Me.OnUnitPriceChanged()
           End If
       End Set
   End Property

備註

當你用來 CreateDatabase 定義欄位包含計算值時，請使用此特性。

例如，如果你想建立一個在 SQL 中定義為 InventoryVal AS UnitPrice * UnitsInStock的欄位，可以使用以下 表達 式字串： "UnitPrice * UnitsInStock"。