Variable.Expression Property

Artigo
12/03/2008

Gets or sets the expression contained in a variable.

Namespace: Microsoft.SqlServer.Dts.Runtime
Assembly: Microsoft.SqlServer.ManagedDTS (in microsoft.sqlserver.manageddts.dll)

Syntax

'Declaration
Public Property Expression As String

public string Expression { get; set; }

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

/** @property */
public String get_Expression ()

/** @property */
public void set_Expression (String value)

public function get Expression () : String

public function set Expression (value : String)

Property Value

A String that contains the expression.

Remarks

The Expression method returns the expression entered in the value property only when the EvaluateAsExpression property is set to true; otherwise, an empty string is returned if false.

Example

The following example sets the EvaluateAsExpression flag to show that the variable contains an expression, and then can use the Expression property.

static void Main(string[] args)
    {
        Package p = new Package();
        p.Variables.Add("x", false, "", 1);
        Variable v = p.Variables.Add("y", false, "", 1);
        v.Expression = "@x + 10";
        v.EvaluateAsExpression = true;
        if (v.Value.ToString() == "11")
            Console.WriteLine("Value was 11");
        else
            Console.WriteLine("Value was not 11");
    }

Shared  Sub Main(ByVal args() As String)
        Dim p As Package =  New Package() 
        p.Variables.Add("x", False, "", 1)
        Dim v As Variable =  p.Variables.Add("y",False,"",1) 
        v.Expression = "@x + 10"
        v.EvaluateAsExpression = True
        If v.Value.ToString() = "11" Then
            Console.WriteLine("Value was 11")
        Else 
            Console.WriteLine("Value was not 11")
        End If
End Sub

Sample Output:

Value was 11

Thread Safety

Any public static (Shared in Microsoft Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Platforms

Development Platforms

For a list of the supported platforms, see Hardware and Software Requirements for Installing SQL Server 2005.

Target Platforms