IsNull 方法

Checks to see if the data in a buffer column is null.

命名空间：  Microsoft.SqlServer.Dts.Pipeline
程序集：  Microsoft.SqlServer.PipelineHost（在 Microsoft.SqlServer.PipelineHost.dll 中）

语法

声明
Public Function IsNull ( _
    columnIndex As Integer _
) As Boolean
用法
Dim instance As PipelineBuffer
Dim columnIndex As Integer
Dim returnValue As Boolean

returnValue = instance.IsNull(columnIndex)

public bool IsNull(
    int columnIndex
)

public:
bool IsNull(
    int columnIndex
)

member IsNull : 
        columnIndex:int -> bool 

public function IsNull(
    columnIndex : int
) : boolean

参数

• columnIndex
  类型：System. . :: . .Int32
  The index of the column in the buffer row.

返回值

类型：System. . :: . .Boolean
true if the column contains nullNothingnullptrunitnull 引用（在 Visual Basic 中为 Nothing）; otherwise, false.

注释

It is recommended that you call the IsNull method prior to calling a data type accessor method, such as GetBoolean, because the PipelineBuffer will produce a ColumnIsNullException if the column is null Nothing nullptr unit null 引用（在 Visual Basic 中为 Nothing） .

请参阅

参考

PipelineBuffer 类

Microsoft.SqlServer.Dts.Pipeline 命名空间