UniqueConstraint Constructors
Definition
Important
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Initializes a new instance of the UniqueConstraint class.
Overloads
UniqueConstraint(DataColumn) |
Initializes a new instance of the UniqueConstraint class with the specified DataColumn. |
UniqueConstraint(DataColumn[]) |
Initializes a new instance of the UniqueConstraint class with the given array of DataColumn objects. |
UniqueConstraint(DataColumn, Boolean) |
Initializes a new instance of the UniqueConstraint class with the DataColumn to constrain, and a value specifying whether the constraint is a primary key. |
UniqueConstraint(DataColumn[], Boolean) |
Initializes a new instance of the UniqueConstraint class with an array of DataColumn objects to constrain, and a value specifying whether the constraint is a primary key. |
UniqueConstraint(String, DataColumn) |
Initializes a new instance of the UniqueConstraint class with the specified name and DataColumn. |
UniqueConstraint(String, DataColumn[]) |
Initializes a new instance of the UniqueConstraint class with the specified name and array of DataColumn objects. |
UniqueConstraint(String, DataColumn, Boolean) |
Initializes a new instance of the UniqueConstraint class with the specified name, the DataColumn to constrain, and a value specifying whether the constraint is a primary key. |
UniqueConstraint(String, DataColumn[], Boolean) |
Initializes a new instance of the UniqueConstraint class with the specified name, an array of DataColumn objects to constrain, and a value specifying whether the constraint is a primary key. |
UniqueConstraint(String, String[], Boolean) |
Initializes a new instance of the UniqueConstraint class with the specified name, an array of DataColumn objects to constrain, and a value specifying whether the constraint is a primary key. |
UniqueConstraint(DataColumn)
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
Initializes a new instance of the UniqueConstraint class with the specified DataColumn.
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)
Parameters
- column
- DataColumn
The DataColumn to constrain.
Examples
The following example creates a new UniqueConstraint and assigns it to the ParentKeyConstraint property of a 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
See also
Applies to
UniqueConstraint(DataColumn[])
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
Initializes a new instance of the UniqueConstraint class with the given array of DataColumn objects.
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())
Parameters
- columns
- DataColumn[]
The array of DataColumn objects to constrain.
See also
Applies to
UniqueConstraint(DataColumn, Boolean)
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
Initializes a new instance of the UniqueConstraint class with the DataColumn to constrain, and a value specifying whether the constraint is a primary key.
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)
Parameters
- column
- DataColumn
The DataColumn to constrain.
- isPrimaryKey
- Boolean
true
to indicate that the constraint is a primary key; otherwise, false
.
See also
Applies to
UniqueConstraint(DataColumn[], Boolean)
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
Initializes a new instance of the UniqueConstraint class with an array of DataColumn objects to constrain, and a value specifying whether the constraint is a primary key.
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)
Parameters
- columns
- DataColumn[]
An array of DataColumn objects to constrain.
- isPrimaryKey
- Boolean
true
to indicate that the constraint is a primary key; otherwise, false
.
See also
Applies to
UniqueConstraint(String, DataColumn)
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
Initializes a new instance of the UniqueConstraint class with the specified name and DataColumn.
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)
Parameters
- name
- String
The name of the constraint.
- column
- DataColumn
The DataColumn to constrain.
Examples
The following example creates a new UniqueConstraint and assigns it to the ParentKeyConstraint property of a 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
See also
Applies to
UniqueConstraint(String, DataColumn[])
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
Initializes a new instance of the UniqueConstraint class with the specified name and array of DataColumn objects.
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())
Parameters
- name
- String
The name of the constraint.
- columns
- DataColumn[]
The array of DataColumn objects to constrain.
Examples
The following example creates a DataTable with two columns, and adds a new UniqueConstraint to the ConstraintCollection.
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
See also
Applies to
UniqueConstraint(String, DataColumn, Boolean)
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
Initializes a new instance of the UniqueConstraint class with the specified name, the DataColumn to constrain, and a value specifying whether the constraint is a primary key.
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)
Parameters
- name
- String
The name of the constraint.
- column
- DataColumn
The DataColumn to constrain.
- isPrimaryKey
- Boolean
true
to indicate that the constraint is a primary key; otherwise, false
.
See also
Applies to
UniqueConstraint(String, DataColumn[], Boolean)
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
Initializes a new instance of the UniqueConstraint class with the specified name, an array of DataColumn objects to constrain, and a value specifying whether the constraint is a primary key.
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)
Parameters
- name
- String
The name of the constraint.
- columns
- DataColumn[]
An array of DataColumn objects to constrain.
- isPrimaryKey
- Boolean
true
to indicate that the constraint is a primary key; otherwise, false
.
See also
Applies to
UniqueConstraint(String, String[], Boolean)
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
- Source:
- UniqueConstraint.cs
Initializes a new instance of the UniqueConstraint class with the specified name, an array of DataColumn objects to constrain, and a value specifying whether the constraint is a primary key.
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)
Parameters
- name
- String
The name of the constraint.
- columnNames
- String[]
An array of DataColumn objects to constrain.
- isPrimaryKey
- Boolean
true
to indicate that the constraint is a primary key; otherwise, false
.
- Attributes
Remarks
This constructor is provided for design time support in the Visual Studio .NET environment. UniqueConstraint objects created by using this constructor must then be added to the collection via AddRange. Columns with the specified names must exist at the time the method is called, or if BeginInit has been called prior to calling this constructor, the columns with the specified names must exist at the time that EndInit is called.