DataTable Class

Definition

Namespace:

System.Data

Assembly:

System.Data.Common.dll

Source:

DataTable.cs

Represents one table of in-memory data.

public ref class DataTable : System::ComponentModel::MarshalByValueComponent, System::ComponentModel::IListSource, System::ComponentModel::ISupportInitialize, System::ComponentModel::ISupportInitializeNotification, System::Runtime::Serialization::ISerializable, System::Xml::Serialization::IXmlSerializable

public class DataTable : System.ComponentModel.MarshalByValueComponent, System.ComponentModel.IListSource, System.ComponentModel.ISupportInitialize, System.ComponentModel.ISupportInitializeNotification, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable

type DataTable = class
    inherit MarshalByValueComponent
    interface IListSource
    interface ISupportInitialize
    interface ISupportInitializeNotification
    interface ISerializable
    interface IXmlSerializable

Public Class DataTable
Inherits MarshalByValueComponent
Implements IListSource, ISerializable, ISupportInitialize, ISupportInitializeNotification, IXmlSerializable

Inheritance

Object

MarshalByValueComponent

DataTable

Derived

System.Data.TypedTableBase<T>

Implements

IListSource ISupportInitialize ISupportInitializeNotification ISerializable IXmlSerializable

Examples

The following example creates two DataTable objects and one DataRelation object, and adds the new objects to a DataSet. The tables are then displayed in a DataGridView control.

// Put the next line into the Declarations section.
private System.Data.DataSet dataSet;

private void MakeDataTables()
{
    // Run all of the functions.
    MakeParentTable();
    MakeChildTable();
    MakeDataRelation();
    BindToDataGrid();
}

private void MakeParentTable()
{
    // Create a new DataTable.
    System.Data.DataTable table = new DataTable("ParentTable");
    // Declare variables for DataColumn and DataRow objects.
    DataColumn column;
    DataRow row;

    // Create new DataColumn, set DataType,
    // ColumnName and add to DataTable.
    column = new DataColumn();
    column.DataType = System.Type.GetType("System.Int32");
    column.ColumnName = "id";
    column.ReadOnly = true;
    column.Unique = true;
    // Add the Column to the DataColumnCollection.
    table.Columns.Add(column);

    // Create second column.
    column = new DataColumn();
    column.DataType = System.Type.GetType("System.String");
    column.ColumnName = "ParentItem";
    column.AutoIncrement = false;
    column.Caption = "ParentItem";
    column.ReadOnly = false;
    column.Unique = false;
    // Add the column to the table.
    table.Columns.Add(column);

    // Make the ID column the primary key column.
    DataColumn[] PrimaryKeyColumns = new DataColumn[1];
    PrimaryKeyColumns[0] = table.Columns["id"];
    table.PrimaryKey = PrimaryKeyColumns;

    // Instantiate the DataSet variable.
    dataSet = new DataSet();
    // Add the new DataTable to the DataSet.
    dataSet.Tables.Add(table);

    // Create three new DataRow objects and add
    // them to the DataTable
    for (int i = 0; i <= 2; i++)
    {
        row = table.NewRow();
        row["id"] = i;
        row["ParentItem"] = "ParentItem " + i;
        table.Rows.Add(row);
    }
}

private void MakeChildTable()
{
    // Create a new DataTable.
    DataTable table = new DataTable("childTable");
    DataColumn column;
    DataRow row;

    // Create first column and add to the DataTable.
    column = new DataColumn();
    column.DataType = System.Type.GetType("System.Int32");
    column.ColumnName = "ChildID";
    column.AutoIncrement = true;
    column.Caption = "ID";
    column.ReadOnly = true;
    column.Unique = true;

    // Add the column to the DataColumnCollection.
    table.Columns.Add(column);

    // Create second column.
    column = new DataColumn();
    column.DataType = System.Type.GetType("System.String");
    column.ColumnName = "ChildItem";
    column.AutoIncrement = false;
    column.Caption = "ChildItem";
    column.ReadOnly = false;
    column.Unique = false;
    table.Columns.Add(column);

    // Create third column.
    column = new DataColumn();
    column.DataType = System.Type.GetType("System.Int32");
    column.ColumnName = "ParentID";
    column.AutoIncrement = false;
    column.Caption = "ParentID";
    column.ReadOnly = false;
    column.Unique = false;
    table.Columns.Add(column);

    dataSet.Tables.Add(table);

    // Create three sets of DataRow objects,
    // five rows each, and add to DataTable.
    for (int i = 0; i <= 4; i++)
    {
        row = table.NewRow();
        row["childID"] = i;
        row["ChildItem"] = "Item " + i;
        row["ParentID"] = 0;
        table.Rows.Add(row);
    }
    for (int i = 0; i <= 4; i++)
    {
        row = table.NewRow();
        row["childID"] = i + 5;
        row["ChildItem"] = "Item " + i;
        row["ParentID"] = 1;
        table.Rows.Add(row);
    }
    for (int i = 0; i <= 4; i++)
    {
        row = table.NewRow();
        row["childID"] = i + 10;
        row["ChildItem"] = "Item " + i;
        row["ParentID"] = 2;
        table.Rows.Add(row);
    }
}

private void MakeDataRelation()
{
    // DataRelation requires two DataColumn
    // (parent and child) and a name.
    DataColumn parentColumn =
        dataSet.Tables["ParentTable"].Columns["id"];
    DataColumn childColumn =
        dataSet.Tables["ChildTable"].Columns["ParentID"];
    DataRelation relation = new
        DataRelation("parent2Child", parentColumn, childColumn);
    dataSet.Tables["ChildTable"].ParentRelations.Add(relation);
}

private void BindToDataGrid()
{
    // Instruct the DataGrid to bind to the DataSet, with the
    // ParentTable as the topmost DataTable.
    DataGrid1.SetDataBinding(dataSet, "ParentTable");
}

' Put the next line into the Declarations section.
private dataSet As DataSet 
 
Private Sub MakeDataTables()
    ' Run all of the functions. 
    MakeParentTable()
    MakeChildTable()
    MakeDataRelation()
    BindToDataGrid()
End Sub
 
Private Sub MakeParentTable()
    ' Create a new DataTable.
    Dim table As New DataTable("ParentTable")

    ' Declare variables for DataColumn and DataRow objects.
    Dim column As DataColumn 
    Dim row As DataRow 
 
    ' Create new DataColumn, set DataType, ColumnName 
    ' and add to DataTable.    
    column = New DataColumn()
    column.DataType = System.Type.GetType("System.Int32")
    column.ColumnName = "id"
    column.ReadOnly = True
    column.Unique = True

    ' Add the Column to the DataColumnCollection.
    table.Columns.Add(column)
 
    ' Create second column.
    column = New DataColumn()
    column.DataType = System.Type.GetType("System.String")
    column.ColumnName = "ParentItem"
    column.AutoIncrement = False
    column.Caption = "ParentItem"
    column.ReadOnly = False
    column.Unique = False

    ' Add the column to the table.
    table.Columns.Add(column)
 
    ' Make the ID column the primary key column.
    Dim PrimaryKeyColumns(0) As DataColumn
    PrimaryKeyColumns(0)= table.Columns("id")
    table.PrimaryKey = PrimaryKeyColumns
 
    ' Instantiate the DataSet variable.
    dataSet = New DataSet()

    ' Add the new DataTable to the DataSet.
    dataSet.Tables.Add(table)
 
    ' Create three new DataRow objects and add 
    ' them to the DataTable
    Dim i As Integer
    For i = 0 to 2
       row = table.NewRow()
       row("id") = i
       row("ParentItem") = "ParentItem " + i.ToString()
       table.Rows.Add(row)
    Next i
End Sub
 
Private Sub MakeChildTable()
    ' Create a new DataTable.
    Dim table As New DataTable("childTable")
    Dim column As DataColumn 
    Dim row As DataRow 
 
    ' Create first column and add to the DataTable.
    column = New DataColumn()
    column.DataType= System.Type.GetType("System.Int32")
    column.ColumnName = "ChildID"
    column.AutoIncrement = True
    column.Caption = "ID"
    column.ReadOnly = True
    column.Unique = True

    ' Add the column to the DataColumnCollection.
    table.Columns.Add(column)
 
    ' Create second column.
    column = New DataColumn()
    column.DataType= System.Type.GetType("System.String")
    column.ColumnName = "ChildItem"
    column.AutoIncrement = False
    column.Caption = "ChildItem"
    column.ReadOnly = False
    column.Unique = False
    table.Columns.Add(column)
 
    ' Create third column.
    column = New DataColumn()
    column.DataType= System.Type.GetType("System.Int32")
    column.ColumnName = "ParentID"
    column.AutoIncrement = False
    column.Caption = "ParentID"
    column.ReadOnly = False
    column.Unique = False
    table.Columns.Add(column)
 
    dataSet.Tables.Add(table)

    ' Create three sets of DataRow objects, five rows each, 
    ' and add to DataTable.
    Dim i As Integer
    For i = 0 to 4
       row = table.NewRow()
       row("childID") = i
       row("ChildItem") = "Item " + i.ToString()
       row("ParentID") = 0 
       table.Rows.Add(row)
    Next i
    For i = 0 to 4
       row = table.NewRow()
       row("childID") = i + 5
       row("ChildItem") = "Item " + i.ToString()
       row("ParentID") = 1 
       table.Rows.Add(row)
    Next i
    For i = 0 to 4
       row = table.NewRow()
       row("childID") = i + 10
       row("ChildItem") = "Item " + i.ToString()
       row("ParentID") = 2 
       table.Rows.Add(row)
    Next i
End Sub
 
Private Sub MakeDataRelation()
    ' DataRelation requires two DataColumn 
    ' (parent and child) and a name.
    Dim parentColumn As DataColumn = _
        dataSet.Tables("ParentTable").Columns("id")
    Dim childColumn As DataColumn = _
        dataSet.Tables("ChildTable").Columns("ParentID")
    Dim relation As DataRelation = new _
        DataRelation("parent2Child", parentColumn, childColumn)
    dataSet.Tables("ChildTable").ParentRelations.Add(relation)
End Sub
 
Private Sub BindToDataGrid()
    ' Instruct the DataGrid to bind to the DataSet, with the 
    ' ParentTable as the topmost DataTable.
    DataGrid1.SetDataBinding(dataSet,"ParentTable")
End Sub

Remarks

For more information about this API, see Supplemental API remarks for DataTable.

Constructors

DataTable()	Initializes a new instance of the DataTable class with no arguments.
DataTable(SerializationInfo, StreamingContext)	Obsolete. Initializes a new instance of the DataTable class with serialized data.
DataTable(String, String)	Initializes a new instance of the DataTable class using the specified table name and namespace.
DataTable(String)	Initializes a new instance of the DataTable class with the specified table name.

Fields

fInitInProgress

Checks whether initialization is in progress. The initialization occurs at run time.

Properties

CaseSensitive	Indicates whether string comparisons within the table are case-sensitive.
ChildRelations	Gets the collection of child relations for this DataTable.
Columns	Gets the collection of columns that belong to this table.
Constraints	Gets the collection of constraints maintained by this table.
Container	Gets the container for the component. (Inherited from MarshalByValueComponent)
DataSet	Gets the DataSet to which this table belongs.
DefaultView	Gets a customized view of the table that may include a filtered view, or a cursor position.
DesignMode	Gets a value indicating whether the component is currently in design mode. (Inherited from MarshalByValueComponent)
DisplayExpression	Gets or sets the expression that returns a value used to represent this table in the user interface. The DisplayExpression property lets you display the name of this table in a user interface.
Events	Gets the list of event handlers that are attached to this component. (Inherited from MarshalByValueComponent)
ExtendedProperties	Gets the collection of customized user information.
HasErrors	Gets a value indicating whether there are errors in any of the rows in any of the tables of the DataSet to which the table belongs.
IsInitialized	Gets a value that indicates whether the DataTable is initialized.
Locale	Gets or sets the locale information used to compare strings within the table.
MinimumCapacity	Gets or sets the initial starting size for this table.
Namespace	Gets or sets the namespace for the XML representation of the data stored in the DataTable.
ParentRelations	Gets the collection of parent relations for this DataTable.
Prefix	Gets or sets the namespace for the XML representation of the data stored in the DataTable.
PrimaryKey	Gets or sets an array of columns that function as primary keys for the data table.
RemotingFormat	Gets or sets the serialization format.
Rows	Gets the collection of rows that belong to this table.
Site	Gets or sets an ISite for the DataTable.
TableName	Gets or sets the name of the DataTable.

Methods

AcceptChanges()	Commits all the changes made to this table since the last time AcceptChanges() was called.
BeginInit()	Begins the initialization of a DataTable that is used on a form or used by another component. The initialization occurs at run time.
BeginLoadData()	Turns off notifications, index maintenance, and constraints while loading data.
Clear()	Clears the DataTable of all data.
Clone()	Clones the structure of the DataTable, including all DataTable schemas and constraints.
Compute(String, String)	Computes the given expression on the current rows that pass the filter criteria.
Copy()	Copies both the structure and data for this DataTable.
CreateDataReader()	Returns a DataTableReader corresponding to the data within this DataTable.
CreateInstance()	Creates a new instance of DataTable.
Dispose()	Releases all resources used by the MarshalByValueComponent. (Inherited from MarshalByValueComponent)
Dispose(Boolean)	Releases the unmanaged resources used by the MarshalByValueComponent and optionally releases the managed resources. (Inherited from MarshalByValueComponent)
EndInit()	Ends the initialization of a DataTable that is used on a form or used by another component. The initialization occurs at run time.
EndLoadData()	Turns on notifications, index maintenance, and constraints after loading data.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetChanges()	Gets a copy of the DataTable that contains all changes made to it since it was loaded or AcceptChanges() was last called.
GetChanges(DataRowState)	Gets a copy of the DataTable containing all changes made to it since it was last loaded, or since AcceptChanges() was called, filtered by DataRowState.
GetDataTableSchema(XmlSchemaSet)	This method returns an XmlSchemaSet instance containing the Web Services Description Language (WSDL) that describes the DataTable for Web Services.
GetErrors()	Gets an array of DataRow objects that contain errors.
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetObjectData(SerializationInfo, StreamingContext)	Obsolete. Populates a serialization information object with the data needed to serialize the DataTable.
GetRowType()	Gets the row type.
GetSchema()	For a description of this member, see GetSchema().
GetService(Type)	Gets the implementer of the IServiceProvider. (Inherited from MarshalByValueComponent)
GetType()	Gets the Type of the current instance. (Inherited from Object)
ImportRow(DataRow)	Copies a DataRow into a DataTable, preserving any property settings, as well as original and current values.
Load(IDataReader, LoadOption, FillErrorEventHandler)	Fills a DataTable with values from a data source using the supplied IDataReader using an error-handling delegate.
Load(IDataReader, LoadOption)	Fills a DataTable with values from a data source using the supplied IDataReader. If the DataTable already contains rows, the incoming data from the data source is merged with the existing rows according to the value of the loadOption parameter.
Load(IDataReader)	Fills a DataTable with values from a data source using the supplied IDataReader. If the DataTable already contains rows, the incoming data from the data source is merged with the existing rows.
LoadDataRow(Object[], Boolean)	Finds and updates a specific row. If no matching row is found, a new row is created using the given values.
LoadDataRow(Object[], LoadOption)	Finds and updates a specific row. If no matching row is found, a new row is created using the given values.
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
Merge(DataTable, Boolean, MissingSchemaAction)	Merge the specified DataTable with the current DataTable, indicating whether to preserve changes and how to handle missing schema in the current DataTable.
Merge(DataTable, Boolean)	Merge the specified DataTable with the current DataTable, indicating whether to preserve changes in the current DataTable.
Merge(DataTable)	Merge the specified DataTable with the current DataTable.
NewRow()	Creates a new DataRow with the same schema as the table.
NewRowArray(Int32)	Returns an array of DataRow.
NewRowFromBuilder(DataRowBuilder)	Creates a new row from an existing row.
OnColumnChanged(DataColumnChangeEventArgs)	Raises the ColumnChanged event.
OnColumnChanging(DataColumnChangeEventArgs)	Raises the ColumnChanging event.
OnPropertyChanging(PropertyChangedEventArgs)	Raises the PropertyChanged event.
OnRemoveColumn(DataColumn)	Notifies the DataTable that a DataColumn is being removed.
OnRowChanged(DataRowChangeEventArgs)	Raises the RowChanged event.
OnRowChanging(DataRowChangeEventArgs)	Raises the RowChanging event.
OnRowDeleted(DataRowChangeEventArgs)	Raises the RowDeleted event.
OnRowDeleting(DataRowChangeEventArgs)	Raises the RowDeleting event.
OnTableCleared(DataTableClearEventArgs)	Raises the TableCleared event.
OnTableClearing(DataTableClearEventArgs)	Raises the TableClearing event.
OnTableNewRow(DataTableNewRowEventArgs)	Raises the TableNewRow event.
ReadXml(Stream)	Reads XML schema and data into the DataTable using the specified Stream.
ReadXml(String)	Reads XML schema and data into the DataTable from the specified file.
ReadXml(TextReader)	Reads XML schema and data into the DataTable using the specified TextReader.
ReadXml(XmlReader)	Reads XML Schema and Data into the DataTable using the specified XmlReader.
ReadXmlSchema(Stream)	Reads an XML schema into the DataTable using the specified stream.
ReadXmlSchema(String)	Reads an XML schema into the DataTable from the specified file.
ReadXmlSchema(TextReader)	Reads an XML schema into the DataTable using the specified TextReader.
ReadXmlSchema(XmlReader)	Reads an XML schema into the DataTable using the specified XmlReader.
ReadXmlSerializable(XmlReader)	Reads from an XML stream.
RejectChanges()	Rolls back all changes that have been made to the table since it was loaded, or the last time AcceptChanges() was called.
Reset()	Resets the DataTable to its original state. Reset removes all data, indexes, relations, and columns of the table. If a DataSet includes a DataTable, the table will still be part of the DataSet after the table is reset.
Select()	Gets an array of all DataRow objects.
Select(String, String, DataViewRowState)	Gets an array of all DataRow objects that match the filter in the order of the sort that match the specified state.
Select(String, String)	Gets an array of all DataRow objects that match the filter criteria, in the specified sort order.
Select(String)	Gets an array of all DataRow objects that match the filter criteria.
ToString()	Gets the TableName and DisplayExpression, if there is one as a concatenated string.
WriteXml(Stream, Boolean)	Writes the current contents of the DataTable as XML using the specified Stream. To save the data for the table and all its descendants, set the writeHierarchy parameter to true.
WriteXml(Stream, XmlWriteMode, Boolean)	Writes the current data, and optionally the schema, for the DataTable to the specified file using the specified XmlWriteMode. To write the schema, set the value for the mode parameter to WriteSchema. To save the data for the table and all its descendants, set the writeHierarchy parameter to true.
WriteXml(Stream, XmlWriteMode)	Writes the current data, and optionally the schema, for the DataTable to the specified file using the specified XmlWriteMode. To write the schema, set the value for the mode parameter to WriteSchema.
WriteXml(Stream)	Writes the current contents of the DataTable as XML using the specified Stream.
WriteXml(String, Boolean)	Writes the current contents of the DataTable as XML using the specified file. To save the data for the table and all its descendants, set the writeHierarchy parameter to true.
WriteXml(String, XmlWriteMode, Boolean)	Writes the current data, and optionally the schema, for the DataTable using the specified file and XmlWriteMode. To write the schema, set the value for the mode parameter to WriteSchema. To save the data for the table and all its descendants, set the writeHierarchy parameter to true.
WriteXml(String, XmlWriteMode)	Writes the current data, and optionally the schema, for the DataTable using the specified file and XmlWriteMode. To write the schema, set the value for the mode parameter to WriteSchema.
WriteXml(String)	Writes the current contents of the DataTable as XML using the specified file.
WriteXml(TextWriter, Boolean)	Writes the current contents of the DataTable as XML using the specified TextWriter. To save the data for the table and all its descendants, set the writeHierarchy parameter to true.
WriteXml(TextWriter, XmlWriteMode, Boolean)	Writes the current data, and optionally the schema, for the DataTable using the specified TextWriter and XmlWriteMode. To write the schema, set the value for the mode parameter to WriteSchema. To save the data for the table and all its descendants, set the writeHierarchy parameter to true.
WriteXml(TextWriter, XmlWriteMode)	Writes the current data, and optionally the schema, for the DataTable using the specified TextWriter and XmlWriteMode. To write the schema, set the value for the mode parameter to WriteSchema.
WriteXml(TextWriter)	Writes the current contents of the DataTable as XML using the specified TextWriter.
WriteXml(XmlWriter, Boolean)	Writes the current contents of the DataTable as XML using the specified XmlWriter.
WriteXml(XmlWriter, XmlWriteMode, Boolean)	Writes the current data, and optionally the schema, for the DataTable using the specified XmlWriter and XmlWriteMode. To write the schema, set the value for the mode parameter to WriteSchema. To save the data for the table and all its descendants, set the writeHierarchy parameter to true.
WriteXml(XmlWriter, XmlWriteMode)	Writes the current data, and optionally the schema, for the DataTable using the specified XmlWriter and XmlWriteMode. To write the schema, set the value for the mode parameter to WriteSchema.
WriteXml(XmlWriter)	Writes the current contents of the DataTable as XML using the specified XmlWriter.
WriteXmlSchema(Stream, Boolean)	Writes the current data structure of the DataTable as an XML schema to the specified stream. To save the schema for the table and all its descendants, set the writeHierarchy parameter to true.
WriteXmlSchema(Stream)	Writes the current data structure of the DataTable as an XML schema to the specified stream.
WriteXmlSchema(String, Boolean)	Writes the current data structure of the DataTable as an XML schema to the specified file. To save the schema for the table and all its descendants, set the writeHierarchy parameter to true.
WriteXmlSchema(String)	Writes the current data structure of the DataTable as an XML schema to the specified file.
WriteXmlSchema(TextWriter, Boolean)	Writes the current data structure of the DataTable as an XML schema using the specified TextWriter. To save the schema for the table and all its descendants, set the writeHierarchy parameter to true.
WriteXmlSchema(TextWriter)	Writes the current data structure of the DataTable as an XML schema using the specified TextWriter.
WriteXmlSchema(XmlWriter, Boolean)	Writes the current data structure of the DataTable as an XML schema using the specified XmlWriter. To save the schema for the table and all its descendants, set the writeHierarchy parameter to true.
WriteXmlSchema(XmlWriter)	Writes the current data structure of the DataTable as an XML schema using the specified XmlWriter.

Events

ColumnChanged	Occurs after a value has been changed for the specified DataColumn in a DataRow.
ColumnChanging	Occurs when a value is being changed for the specified DataColumn in a DataRow.
Disposed	Adds an event handler to listen to the Disposed event on the component. (Inherited from MarshalByValueComponent)
Initialized	Occurs after the DataTable is initialized.
RowChanged	Occurs after a DataRow has been changed successfully.
RowChanging	Occurs when a DataRow is changing.
RowDeleted	Occurs after a row in the table has been deleted.
RowDeleting	Occurs before a row in the table is about to be deleted.
TableCleared	Occurs after a DataTable is cleared.
TableClearing	Occurs when a DataTable is cleared.
TableNewRow	Occurs when a new DataRow is inserted.

Explicit Interface Implementations

IListSource.ContainsListCollection	For a description of this member, see ContainsListCollection.
IListSource.GetList()	For a description of this member, see GetList().
IXmlSerializable.GetSchema()	For a description of this member, see GetSchema().
IXmlSerializable.ReadXml(XmlReader)	For a description of this member, see ReadXml(XmlReader).
IXmlSerializable.WriteXml(XmlWriter)	For a description of this member, see WriteXml(XmlWriter).

Extension Methods

AsDataView(DataTable)	Creates and returns a LINQ-enabled DataView object.
AsEnumerable(DataTable)	Returns an IEnumerable<T> object, where the generic parameter T is DataRow. This object can be used in a LINQ expression or method query.

Thread Safety

This type is safe for multithreaded read operations. You must synchronize any write operations.

See also

• DataTables