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DataRow.IsNull Method
Definition
- Namespace:
- System.Data
- Assemblies:
- netstandard.dll, System.Data.Common.dll
- Assembly:
- System.Data.Common.dll
- Assembly:
- System.Data.dll
- Assembly:
- netstandard.dll
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Gets a value that indicates whether the specified column contains a null value.
Overloads
| Name | Description |
|---|---|
| IsNull(DataColumn) |
Gets a value that indicates whether the specified DataColumn contains a null value. |
| IsNull(Int32) |
Gets a value that indicates whether the column at the specified index contains a null value. |
| IsNull(String) |
Gets a value that indicates whether the named column contains a null value. |
| IsNull(DataColumn, DataRowVersion) |
Gets a value that indicates whether the specified DataColumn and DataRowVersion contains a null value. |
IsNull(DataColumn)
- Source:
- DataRow.cs
- Source:
- DataRow.cs
- Source:
- DataRow.cs
- Source:
- DataRow.cs
- Source:
- DataRow.cs
Gets a value that indicates whether the specified DataColumn contains a null value.
public:
bool IsNull(System::Data::DataColumn ^ column);public bool IsNull(System.Data.DataColumn column);member this.IsNull : System.Data.DataColumn -> boolPublic Function IsNull (column As DataColumn) As BooleanParameters
- column
- DataColumn
A DataColumn.
Returns
true if the column contains a null value; otherwise, false.
Exceptions
column is null.
The row does not belong to the table.
Examples
The following example prints each column of each row in each table of a DataSet. If the row is set to a null value, the value is not printed.
Private Sub PrintRows(dataSet As DataSet)
Dim table As DataTable
Dim column As DataColumn
Dim row As DataRow
For Each table In dataSet.Tables
For Each row In table.Rows
For Each column In table.Columns
If Not row.IsNull(column) Then
Console.WriteLine(row(column).ToString())
End If
Next column
Next row
Next table
End Sub
Applies to
IsNull(Int32)
- Source:
- DataRow.cs
- Source:
- DataRow.cs
- Source:
- DataRow.cs
- Source:
- DataRow.cs
- Source:
- DataRow.cs
Gets a value that indicates whether the column at the specified index contains a null value.
public:
bool IsNull(int columnIndex);public bool IsNull(int columnIndex);member this.IsNull : int -> boolPublic Function IsNull (columnIndex As Integer) As BooleanParameters
- columnIndex
- Int32
The zero-based index of the column.
Returns
true if the column contains a null value; otherwise, false.
Exceptions
No column corresponds to the index specified by columnIndex.
The row does not belong to the table.
Examples
The following example changes the value of a column to a null value, and then uses the IsNull method to determine whether the value is null.
Private Sub IsValNull()
' Assuming the DataGrid is bound to a DataTable.
Dim table As DataTable = CType(DataGrid1.DataSource, DataTable)
Dim row As DataRow = table.Rows(datagrid1.CurrentCell.RowNumber)
row.BeginEdit
row(1) = System.DBNull.Value
row.EndEdit
row.AcceptChanges
Console.WriteLine(row.IsNull(1))
End Sub
Applies to
IsNull(String)
- Source:
- DataRow.cs
- Source:
- DataRow.cs
- Source:
- DataRow.cs
- Source:
- DataRow.cs
- Source:
- DataRow.cs
Gets a value that indicates whether the named column contains a null value.
public:
bool IsNull(System::String ^ columnName);public bool IsNull(string columnName);member this.IsNull : string -> boolPublic Function IsNull (columnName As String) As BooleanParameters
- columnName
- String
The name of the column.
Returns
true if the column contains a null value; otherwise, false.
Exceptions
The column specified by columnName cannot be found.
columnName is null.
The row does not belong to the table.
Examples
The following example changes the value of a column to a null value, and then uses the IsNull method to determine whether the value is null.
Private Sub IsValNull()
' Assuming the DataGrid is bound to a DataTable.
Dim table As DataTable = CType(DataGrid1.DataSource, DataTable)
Dim row As DataRow = table.Rows(datagrid1.CurrentCell.RowNumber)
row.BeginEdit
row("FirstName") = System.DBNull.Value
row.EndEdit
row.AcceptChanges
Console.WriteLine(row.IsNull("FirstName"))
End Sub
Applies to
IsNull(DataColumn, DataRowVersion)
- Source:
- DataRow.cs
- Source:
- DataRow.cs
- Source:
- DataRow.cs
- Source:
- DataRow.cs
- Source:
- DataRow.cs
Gets a value that indicates whether the specified DataColumn and DataRowVersion contains a null value.
public:
bool IsNull(System::Data::DataColumn ^ column, System::Data::DataRowVersion version);public bool IsNull(System.Data.DataColumn column, System.Data.DataRowVersion version);member this.IsNull : System.Data.DataColumn * System.Data.DataRowVersion -> boolPublic Function IsNull (column As DataColumn, version As DataRowVersion) As BooleanParameters
- column
- DataColumn
A DataColumn.
- version
- DataRowVersion
One of the DataRowVersion values that specifies the row version. Possible values are Default, Original, Current, and Proposed.
Returns
true if the column contains a null value; otherwise, false.
Exceptions
column is null.
The row does not belong to the table.
The row does not have the requested version.
Applies to
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