ScriptBuffer.IsNull 方法
Returns a value that indicates whether the value of the specified column is nullnull 引用（在 Visual Basic 中为 Nothing）.
命名空间： Microsoft.SqlServer.Dts.Pipeline
程序集： Microsoft.SqlServer.TxScript（在 Microsoft.SqlServer.TxScript.dll 中）
语法
声明
Protected Function IsNull ( _
ColumnIndex As Integer _
) As Boolean
用法
Dim ColumnIndex As Integer
Dim returnValue As Boolean
returnValue = Me.IsNull(ColumnIndex)
protected bool IsNull(
int ColumnIndex
)
protected:
bool IsNull(
int ColumnIndex
)
member IsNull :
ColumnIndex:int -> bool
protected function IsNull(
ColumnIndex : int
) : boolean
参数
- ColumnIndex
类型：System.Int32
The index of the column.
返回值
类型：System.Boolean
true if the value of the specified column is nullnull 引用（在 Visual Basic 中为 Nothing）; otherwise, false.
注释
The Script component developer does not use the ScriptBuffer class directly, but indirectly, through the derived classes in the BufferWrapper project item that represent the component's input and outputs.
The developer does not have to use the IsNull method, because the derived classes contain a <ColumnX>_IsNull property for each column.
示例
The following sample code from the autogenerated BufferWrapper project item demonstrates how the Script component uses the IsNull method.
Public Property [city_IsNull] As Boolean
Get
Return IsNull(1)
End Get
Set
SetNull(1)
End Set
End Property