UniqueConstraint 建構函式

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

public:
 UniqueConstraint(System::Data::DataColumn ^ column);

public UniqueConstraint(System.Data.DataColumn column);

new System.Data.UniqueConstraint : System.Data.DataColumn -> System.Data.UniqueConstraint

Public Sub New (column As DataColumn)

參數

範例

以下範例建立一個新 UniqueConstraint ，並將其指派到 ParentKeyConstraint 的屬性 DataRelation。

Private Sub CreateUniqueConstraint(ByVal dataSetSuppliers As DataSet)
    Dim uniqueConstraint As UniqueConstraint

    ' Get the DataColumn of a table in a DataSet.
    Dim dataColumn As DataColumn
    dataColumn = dataSetSuppliers.Tables("Suppliers").Columns("SupplierID")

    ' Create the constraint.
    uniqueConstraint = New UniqueConstraint("supplierIdConstraint", dataColumn)

    ' Add the constraint to the ConstraintCollection of the DataTable.
    dataSetSuppliers.Tables("Suppliers").Constraints.Add(uniqueConstraint)
End Sub

另請參閱

• 將條件約束新增至數據表

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

public:
 UniqueConstraint(cli::array <System::Data::DataColumn ^> ^ columns);

public UniqueConstraint(System.Data.DataColumn[] columns);

new System.Data.UniqueConstraint : System.Data.DataColumn[] -> System.Data.UniqueConstraint

Public Sub New (columns As DataColumn())

參數

另請參閱

• 將條件約束新增至數據表

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

public:
 UniqueConstraint(System::Data::DataColumn ^ column, bool isPrimaryKey);

public UniqueConstraint(System.Data.DataColumn column, bool isPrimaryKey);

new System.Data.UniqueConstraint : System.Data.DataColumn * bool -> System.Data.UniqueConstraint

Public Sub New (column As DataColumn, isPrimaryKey As Boolean)

參數

另請參閱

• 將條件約束新增至數據表

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

public:
 UniqueConstraint(cli::array <System::Data::DataColumn ^> ^ columns, bool isPrimaryKey);

public UniqueConstraint(System.Data.DataColumn[] columns, bool isPrimaryKey);

new System.Data.UniqueConstraint : System.Data.DataColumn[] * bool -> System.Data.UniqueConstraint

Public Sub New (columns As DataColumn(), isPrimaryKey As Boolean)

參數

另請參閱

• 將條件約束新增至數據表

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

public:
 UniqueConstraint(System::String ^ name, System::Data::DataColumn ^ column);

public UniqueConstraint(string? name, System.Data.DataColumn column);

public UniqueConstraint(string name, System.Data.DataColumn column);

new System.Data.UniqueConstraint : string * System.Data.DataColumn -> System.Data.UniqueConstraint

Public Sub New (name As String, column As DataColumn)

參數

範例

以下範例建立一個新 UniqueConstraint ，並將其指派到 ParentKeyConstraint 的屬性 DataRelation。

Private Sub CreateUniqueConstraint(ByVal dataSetSuppliers As DataSet)
    Dim uniqueConstraint As UniqueConstraint

    ' Get the DataColumn of a table in a DataSet.
    Dim dataColumn As DataColumn
    dataColumn = dataSetSuppliers.Tables("Suppliers").Columns("SupplierID")

    ' Create the constraint.
    uniqueConstraint = New UniqueConstraint("supplierIdConstraint", dataColumn)

    ' Add the constraint to the ConstraintCollection of the DataTable.
    dataSetSuppliers.Tables("Suppliers").Constraints.Add(uniqueConstraint)
End Sub

另請參閱

• DataRelation
• ParentKeyConstraint
• 將條件約束新增至數據表

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

public:
 UniqueConstraint(System::String ^ name, cli::array <System::Data::DataColumn ^> ^ columns);

public UniqueConstraint(string? name, System.Data.DataColumn[] columns);

public UniqueConstraint(string name, System.Data.DataColumn[] columns);

new System.Data.UniqueConstraint : string * System.Data.DataColumn[] -> System.Data.UniqueConstraint

Public Sub New (name As String, columns As DataColumn())

參數

範例

以下範例建立兩欄的 ， DataTable 並在 中加入新的 UniqueConstraintConstraintCollection。

static private void MakeTableWithUniqueConstraint()
{
    // Create a DataTable with 2 DataColumns.
    DataTable dataTable = new DataTable("dataTable");
    DataColumn idColumn = new DataColumn(
        "id", System.Type.GetType("System.Int32"));
    DataColumn nameColumn = new DataColumn(
        "Name", System.Type.GetType("System.String"));
    dataTable.Columns.Add(idColumn);
    dataTable.Columns.Add(nameColumn);

    // Run procedure to create a constraint.
    AddUniqueConstraint(dataTable);

    // Add one row to the table.
    DataRow dataRow;
    dataRow = dataTable.NewRow();
    dataRow["id"] = 1;
    dataRow["Name"] = "John";
    dataTable.Rows.Add(dataRow);

    // Display the constraint name.
    Console.WriteLine(
        dataTable.Constraints[0].ConstraintName);

    // Try to add an identical row,
    // which throws an exception.
    try
    {
        dataRow = dataTable.NewRow();
        dataRow["id"] = 1;
        dataRow["Name"] = "John";
        dataTable.Rows.Add(dataRow);
    }
    catch (Exception ex)
    {
        Console.WriteLine(
            "Exception Type: {0}", ex.GetType());
        Console.WriteLine(
            "Exception Message: {0}", ex.Message);
    }
}
static private void AddUniqueConstraint(
    DataTable dataTable)
{
    // Create the DataColumn array.
    DataColumn[] dataColumns = new DataColumn[2];
    dataColumns[0] = dataTable.Columns["id"];
    dataColumns[1] = dataTable.Columns["Name"];

    // Create the constraint on both columns.
    UniqueConstraint uniqueConstraint =
        new UniqueConstraint("idNameConstraint", dataColumns);
    dataTable.Constraints.Add(uniqueConstraint);
}

Private Sub MakeTableWithUniqueConstraint()
    ' Create a DataTable with 2 DataColumns.
    Dim dataTable As New DataTable("dataTable")
    Dim idColumn As New DataColumn( _
        "ID", System.Type.GetType("System.Int32"))
    Dim nameColumn As New DataColumn( _
        "Name", System.Type.GetType("System.String"))
    dataTable.Columns.Add(idColumn)
    dataTable.Columns.Add(nameColumn)

    ' Run procedure to create a constraint.
    AddUniqueConstraint(dataTable)

    ' Add one row to the table.
    Dim dataRow As DataRow
    dataRow = dataTable.NewRow()
    dataRow("ID") = 1
    dataRow("Name") = "John"
    dataTable.Rows.Add(dataRow)

    ' Display the constraint name.
    Console.WriteLine(dataTable.Constraints(0).ConstraintName)

    ' Try to add an identical row,
    ' which throws an exception.
    Try
        dataRow = dataTable.NewRow()
        dataRow("ID") = 1
        dataRow("Name") = "John"
        dataTable.Rows.Add(dataRow)
    Catch ex As Exception
        Console.WriteLine("Exception Type: {0}", ex.GetType())
        Console.WriteLine("Exception Message: {0}", ex.Message)
    End Try
End Sub

Private Sub AddUniqueConstraint(ByVal dataTable As DataTable)
    ' Create the DataColumn array.
    Dim dataColumns(1) As DataColumn
    dataColumns(0) = dataTable.Columns("ID")
    dataColumns(1) = dataTable.Columns("Name")

    ' Create the constraint on both columns.
    Dim uniqueConstraint As UniqueConstraint = _
        New UniqueConstraint("idNameConstraint", dataColumns)
    dataTable.Constraints.Add(uniqueConstraint)
End Sub

另請參閱

• 將條件約束新增至數據表

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

public:
 UniqueConstraint(System::String ^ name, System::Data::DataColumn ^ column, bool isPrimaryKey);

public UniqueConstraint(string? name, System.Data.DataColumn column, bool isPrimaryKey);

public UniqueConstraint(string name, System.Data.DataColumn column, bool isPrimaryKey);

new System.Data.UniqueConstraint : string * System.Data.DataColumn * bool -> System.Data.UniqueConstraint

Public Sub New (name As String, column As DataColumn, isPrimaryKey As Boolean)

參數

另請參閱

• 將條件約束新增至數據表

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

public:
 UniqueConstraint(System::String ^ name, cli::array <System::Data::DataColumn ^> ^ columns, bool isPrimaryKey);

public UniqueConstraint(string? name, System.Data.DataColumn[] columns, bool isPrimaryKey);

public UniqueConstraint(string name, System.Data.DataColumn[] columns, bool isPrimaryKey);

new System.Data.UniqueConstraint : string * System.Data.DataColumn[] * bool -> System.Data.UniqueConstraint

Public Sub New (name As String, columns As DataColumn(), isPrimaryKey As Boolean)

參數

另請參閱

• 將條件約束新增至數據表

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

來源:

UniqueConstraint.cs

public:
 UniqueConstraint(System::String ^ name, cli::array <System::String ^> ^ columnNames, bool isPrimaryKey);

[System.ComponentModel.Browsable(false)]
public UniqueConstraint(string? name, string[]? columnNames, bool isPrimaryKey);

[System.ComponentModel.Browsable(false)]
public UniqueConstraint(string name, string[] columnNames, bool isPrimaryKey);

[<System.ComponentModel.Browsable(false)>]
new System.Data.UniqueConstraint : string * string[] * bool -> System.Data.UniqueConstraint

Public Sub New (name As String, columnNames As String(), isPrimaryKey As Boolean)

參數

屬性

BrowsableAttribute

備註

此建構器用於 Visual Studio .NET 環境的設計階段支援。 UniqueConstraint 使用此建構子建立的物件必須透過 AddRange加入集合。 指定名稱的欄位必須在呼叫方法時存在，或者如果 BeginInit 在呼叫建構子之前已被呼叫，則指定名稱的欄位必須在 EndInit 呼叫時存在。

另請參閱

• 將條件約束新增至數據表