DataTable Kelas

Definisi

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 ref class DataTable

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

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

[System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembers(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.NonPublicConstructors | System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicParameterlessConstructor)]
public 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

public class DataTable

[System.Serializable]
public class DataTable : System.ComponentModel.MarshalByValueComponent, System.ComponentModel.IListSource, System.ComponentModel.ISupportInitialize, System.Runtime.Serialization.ISerializable

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

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

[<System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembers(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.NonPublicConstructors | System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicParameterlessConstructor)>]
type DataTable = class
    inherit MarshalByValueComponent
    interface IListSource
    interface ISupportInitialize
    interface ISupportInitializeNotification
    interface ISerializable
    interface IXmlSerializable

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

type DataTable = class

[<System.Serializable>]
type DataTable = class
    inherit MarshalByValueComponent
    interface IListSource
    interface ISupportInitialize
    interface ISerializable

[<System.Serializable>]
type DataTable = class
    inherit MarshalByValueComponent
    interface IListSource
    interface ISupportInitializeNotification
    interface ISupportInitialize
    interface ISerializable
    interface IXmlSerializable

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

Public Class DataTable

Public Class DataTable
Inherits MarshalByValueComponent
Implements IListSource, ISerializable, ISupportInitialize

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

Warisan

Object

MarshalByValueComponent

DataTable

Warisan

Object

DataTable

Turunan

System.Data.TypedTableBase<T>

Atribut

DynamicallyAccessedMembersAttribute SerializableAttribute

Penerapan

IListSource ISupportInitialize ISupportInitializeNotification ISerializable IXmlSerializable

Contoh

Sampel ini menunjukkan cara membuat DataTable secara manual dengan definisi skema tertentu:

• Buat beberapa DataTable dan tentukan kolom awal.
• Buat batasan tabel.
• Sisipkan nilai dan tampilkan tabel.
• Buat kolom ekspresi dan tampilkan tabel.

using System;
using System.Data;

class Program
{
    static void Main()
    {
        // Create two tables and add them into the DataSet.
        DataTable orderTable = CreateOrderTable();
        DataTable orderDetailTable = CreateOrderDetailTable();
        DataSet salesSet = new();
        salesSet.Tables.Add(orderTable);
        salesSet.Tables.Add(orderDetailTable);

        // Set the relations between the tables
        // and create the related constraint.
        salesSet.Relations.Add(
            "OrderOrderDetail",
            orderTable.Columns["OrderId"],
            orderDetailTable.Columns["OrderId"],
            true);

        Console.WriteLine("After creating the foreign key constraint, " +
            "you'll see the following error if you insert " +
            "an order detail with the wrong OrderId:\n");
        try
        {
            DataRow errorRow = orderDetailTable.NewRow();
            errorRow[0] = 1;
            errorRow[1] = "O0007";
            orderDetailTable.Rows.Add(errorRow);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
        Console.WriteLine();

        // Insert the rows into the table.
        InsertOrders(orderTable);
        InsertOrderDetails(orderDetailTable);

        Console.WriteLine("The initial Order table.");
        ShowTable(orderTable);

        Console.WriteLine("The OrderDetail table.");
        ShowTable(orderDetailTable);

        // Use the Aggregate-Sum on the child table column to get the result.
        DataColumn colSub = new("SubTotal", typeof(decimal), "Sum(Child.LineTotal)");
        orderTable.Columns.Add(colSub);

        // Compute the tax by referencing the SubTotal expression column.
        DataColumn colTax = new("Tax", typeof(decimal), "SubTotal*0.1");
        orderTable.Columns.Add(colTax);

        // If the OrderId is 'Total', compute the amount due on all orders; otherwise, compute the amount due on this order.
        DataColumn colTotal = new(
            "TotalDue",
            typeof(decimal),
            "IIF(OrderId='Total',Sum(SubTotal)+Sum(Tax),SubTotal+Tax)");
        orderTable.Columns.Add(colTotal);

        DataRow row = orderTable.NewRow();
        row["OrderId"] = "Total";
        orderTable.Rows.Add(row);

        Console.WriteLine("The Order table with the expression columns.");
        ShowTable(orderTable);

        Console.WriteLine("Press any key to exit.....");
        Console.ReadKey();
    }

    private static DataTable CreateOrderTable()
    {
        DataTable orderTable = new("Order");

        // Define the columns one at a time.
        DataColumn colId = new("OrderId", typeof(string));
        orderTable.Columns.Add(colId);

        DataColumn colDate = new("OrderDate", typeof(DateTime));
        orderTable.Columns.Add(colDate);

        // Set the OrderId column as the primary key.
        orderTable.PrimaryKey = [colId];

        return orderTable;
    }

    private static DataTable CreateOrderDetailTable()
    {
        DataTable orderDetailTable = new("OrderDetail");

        // Define all the columns at once.
        DataColumn[] cols =
        [
            new DataColumn("OrderDetailId", typeof(int)),
            new DataColumn("OrderId", typeof(string)),
            new DataColumn("Product", typeof(string)),
            new DataColumn("UnitPrice", typeof(decimal)),
            new DataColumn("OrderQty", typeof(int)),
            new DataColumn("LineTotal", typeof(decimal), "UnitPrice*OrderQty")
        ];

        orderDetailTable.Columns.AddRange(cols);
        orderDetailTable.PrimaryKey = [orderDetailTable.Columns["OrderDetailId"]];
        return orderDetailTable;
    }

    private static void InsertOrders(DataTable orderTable)
    {
        // Add one row at a time.
        DataRow row1 = orderTable.NewRow();
        row1["OrderId"] = "O0001";
        row1["OrderDate"] = new DateTime(2013, 3, 1);
        orderTable.Rows.Add(row1);

        DataRow row2 = orderTable.NewRow();
        row2["OrderId"] = "O0002";
        row2["OrderDate"] = new DateTime(2013, 3, 12);
        orderTable.Rows.Add(row2);

        DataRow row3 = orderTable.NewRow();
        row3["OrderId"] = "O0003";
        row3["OrderDate"] = new DateTime(2013, 3, 20);
        orderTable.Rows.Add(row3);
    }

    private static void InsertOrderDetails(DataTable orderDetailTable)
    {
        // Use an Object array to insert all the rows.
        // Values in the array are matched sequentially to the columns,
        // based on the order in which they appear in the table.
        object[][] rows =
        [
            [1, "O0001", "Mountain Bike", 1419.5, 36],
            [2, "O0001", "Road Bike", 1233.6, 16],
            [3, "O0001", "Touring Bike", 1653.3, 32],
            [4, "O0002", "Mountain Bike", 1419.5, 24],
            [5, "O0002", "Road Bike", 1233.6, 12],
            [6, "O0003", "Mountain Bike", 1419.5, 48],
            [7, "O0003", "Touring Bike", 1653.3, 8],
        ];

        foreach (object[] row in rows)
        {
            orderDetailTable.Rows.Add(row);
        }
    }

    private static void ShowTable(DataTable table)
    {
        foreach (DataColumn col in table.Columns)
        {
            Console.Write("{0,-14}", col.ColumnName);
        }
        Console.WriteLine();

        foreach (DataRow row in table.Rows)
        {
            foreach (DataColumn col in table.Columns)
            {
                if (col.DataType.Equals(typeof(DateTime)))
                    Console.Write("{0,-14:d}", row[col]);
                else if (col.DataType.Equals(typeof(decimal)))
                    Console.Write("{0,-14:C}", row[col]);
                else
                    Console.Write("{0,-14}", row[col]);
            }
            Console.WriteLine();
        }
        Console.WriteLine();
    }
}

' 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

Keterangan

Kelas DataTable adalah objek pusat di pustaka ADO.NET. Objek lain yang menggunakan DataTable termasuk DataSet dan DataView.

DataTable nama objek peka terhadap huruf besar-kecil secara kondisional. Misalnya, jika satu DataTable diberi nama "mydatatable" dan yang lain diberi nama "Mydatatable", string yang digunakan untuk mencari salah satu tabel dianggap sebagai peka terhadap huruf besar/kecil. Namun, jika "mydatatable" ada dan "Mydatatable" tidak, string pencarian dianggap tidak membedakan huruf besar atau kecil. DataSet Dapat berisi dua DataTable objek yang memiliki nilai properti yang sama TableName tetapi nilai properti yang berbedaNamespace. Untuk informasi selengkapnya tentang bekerja dengan DataTable objek, lihat Membuat DataTable.

Jika Anda membuat DataTable secara terprogram, Anda harus terlebih dahulu menentukan skemanya dengan menambahkan objek DataColumn ke dalam DataColumnCollection (dapat diakses melalui properti Columns). Untuk informasi selengkapnya tentang menambahkan DataColumn objek, lihat Menambahkan Kolom ke DataTable.

Untuk menambahkan baris ke DataTable, Anda harus terlebih dahulu menggunakan NewRow metode untuk mengembalikan objek baru DataRow . Metode NewRow mengembalikan baris dengan skema DataTable, seperti yang didefinisikan oleh tabel DataColumnCollection. Jumlah maksimum baris yang DataTable dapat disimpan adalah 16.777.216. Untuk informasi selengkapnya, lihat Menambahkan Data ke DataTable.

juga DataTable berisi kumpulan Constraint objek yang dapat digunakan untuk memastikan integritas data. Untuk informasi selengkapnya, lihat Batasan DataTable.

Ada banyak DataTable peristiwa yang dapat digunakan untuk menentukan kapan perubahan dilakukan pada tabel. Ini termasuk RowChanged, RowChanging, RowDeleting, dan RowDeleted. Untuk informasi selengkapnya tentang event yang dapat digunakan dengan DataTable, lihat Menangani Event DataTable.

Saat instans DataTable dibuat, beberapa properti baca/tulis diatur ke nilai awal. Untuk daftar nilai-nilai ini, lihat DataTable konstruktor.

Pertimbangan keamanan

Untuk informasi tentang keamanan Himpunan Data dan DataTable, lihat Panduan keamanan.

Keamanan Thread

Jenis ini aman untuk operasi baca multithreaded. Anda harus menyinkronkan operasi tulis apa pun.

Lihat juga

• DataTables