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c# - How to add a new row into DataTable

Add a new row to the DataTable
The DataTable class represents one table of in-memory data. The DataTable objects are conditionally case-sensitive. To create a DataTable programmatically the asp.net developers must first define its schema by adding DataColumn objects to the DataColumnCollection. To add rows to a DataTable, the developers must use the NewRow() method to return a new DataRow object at first. The DataTable also contains a collection of Constraint objects that can be used to ensure the integrity of the data.

The following asp.net c# tutorial code demonstrates how we can add a new row into a DataTable. So we have to add a new DataRow object into the DataTable.

Here we used the DataTable class Rows property to get its rows collection as a DataRowCollection object. Then we used DataRowCollection’s Add() method to add a new DataRow object to the rows collections.

The DataTable class Rows property gets the collection of rows that belong to this table. The Rows property value is a DataRowCollection that contains DataRow objects. Each DataRow in the collection represents a row of data in the table. The DataRowCollection class represents a collection of rows for a DataTable.

The DataRowCollection Add() method adds a DataRow to the DataRowCollection. The Add(DataRow) method overload adds the specified DataRow to the DataRowCollection object. The Add(System.Data.DataRow row) method has a parameter named row. The row parameter is the DataRow to add.

The Add(System.Data.DataRow row) method throws ArgumentNullException if the row is null. The method throws ArgumentException if the row either belongs to another table or already belongs to this table. And it throws ConstraintException if the addition invalidates a constraint. It also throws NoNullAllowedException if the addition tries to put a null in a DataColumn where AllowDBNull is false.

To create a new DataRow, the asp.net web developers must use the NewRow() method of the DataTable class. When they use the NewRow method, a new DataRow object is returned using the schema of the parent DataTable. After developers create the DataRow object and set the values for each of its columns, then they have to use the Add() method to add the object to the collection.

So finally, using the DataTable class Rows property the asp.net web developers can get the DataRowCollection object. And the DataRowCollection class Add() method allows the asp.net web developers to add a new row to the row collection in a DataTable.
AddDataRowToDataTable.aspx

<%@ Page Language="C#" AutoEventWireup="true" %>
<%@ Import Namespace="System.Data" %>

<!DOCTYPE html>
<script runat="server">
    void Button1_Click(object sender, System.EventArgs e)
    {
        DataTable dt = new DataTable();
        dt.TableName = "Books";

        DataColumn dc1 = new DataColumn();
        dc1.ColumnName = "BookID";
        dc1.DataType = typeof(int);
        dc1.AllowDBNull = false;

        DataColumn dc2 = new DataColumn();
        dc2.ColumnName = "BookName";
        dc2.DataType = typeof(string);

        DataColumn dc3 = new DataColumn();
        dc3.ColumnName = "Author";
        dc3.DataType = typeof(string);

        dt.Columns.AddRange(new DataColumn[] { dc1,dc2,dc3 });

        dt.Rows.Add(new object[] { 1, "Learning ActionScript 3.0, Second Edition", "Rich Shupe" });
        dt.Rows.Add(new object[] { 2, "Flash CS5: The Missing Manual", "Chris Grover" });

        GridView1.DataSource = dt;
        GridView1.DataBind();

        //add another one DataRow in DataTable
        DataRow dr = dt.NewRow();
        dr["BookID"] = 3;
        dr["BookName"] = "Google SketchUp: The Missing Manual";
        dr["Author"] = "Chris Grover";
        dt.Rows.Add(dr);

        Label1.Text = "add another one DataRow into DataTable";

        GridView2.DataSource = dt;
        GridView2.DataBind();
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>How to add DataRow to DataTable in ado.net</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <h2 style="color:DarkBlue; font-style:italic;">
            How to add DataRow to DataTable in ado.net
        </h2>
        <hr width="500" align="left" color="CornFlowerBlue" />
        <asp:GridView 
            ID="GridView1"
            runat="server"
            BorderColor="Snow"
            ForeColor="Snow"
            Width="550"
            >
            <HeaderStyle BackColor="Crimson" Height="35" />
            <RowStyle BackColor="DodgerBlue" />
            <AlternatingRowStyle BackColor="SkyBlue" />
        </asp:GridView>
        <br />
        <asp:Label
             ID="Label1"
             runat="server"
             Font-Size="Medium"
             ForeColor="HotPink"
             >
        </asp:Label>
        <br /><br />
        <asp:GridView 
            ID="GridView2"
            runat="server"
            BorderColor="Snow"
            ForeColor="Snow"
            Width="550"
            >
            <HeaderStyle BackColor="Crimson" Height="35" />
            <RowStyle BackColor="DodgerBlue" />
            <AlternatingRowStyle BackColor="SkyBlue" />
        </asp:GridView>
        <asp:Button 
            ID="Button1"
            runat="server"
            OnClick="Button1_Click"
            Text="Populate GridView"
            Height="45"
            Font-Bold="true"
            ForeColor="DarkBlue"
            />
    </div>
    </form>
</body>
</html>
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