в 15:30, 26 мая 2010

2010-05-26T15:30:57Z

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2010-05-26T11:56:41Z

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== Build a DataTable==



<source lang="csharp">
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="UsingDataTable" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Using DataTable</title>
</head>
<body>
<form id="form1" runat="server">
<div id="container">
<asp:ListBox ID="lboxTable" runat="server"
DataTextField="FullName"
DataValueField="Id" />

</div>
</form>
</body>
</html>
File: Default.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class UsingDataTable : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
DataTable table = new DataTable();
DataColumn idCol = new DataColumn();
idCol.ColumnName = "Id";
idCol.DataType = typeof(Int32);
idCol.AllowDBNull = false;
idCol.Unique = true;
idCol.AutoIncrement = true;
DataColumn firstNameCol = new DataColumn("FirstName", typeof(string));
DataColumn lastNameCol = new DataColumn("LastName", typeof(string));
DataColumn phoneCol = new DataColumn("Phone", typeof(string));
DataColumn nameCol = new DataColumn("FullName", typeof(string));
nameCol.Expression = "LastName + ", " + FirstName";
table.Columns.Add(idCol);
table.Columns.Add(firstNameCol);
table.Columns.Add(lastNameCol);
table.Columns.Add(phoneCol);
table.Columns.Add(nameCol);
DataRow r1 = table.NewRow();
r1[1] = "A";
r1[2] = "B";
r1[3] = "123-4567";
table.Rows.Add(r1);
DataRow r2 = table.NewRow();
r2["FirstName"] = "C";
r2["LastName"] = "D";
r2["Phone"] = "564-7823";
table.Rows.Add(r2);
lboxTable.DataSource = table;
lboxTable.DataBind();
}
}</source>

== Create and display in-memory calculated fields==



<source lang="csharp">
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs"
Inherits="Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Cities and Customers</title>
</head>
<body>
<div id="pageContent">
<form id="form1" runat="server">
<h2>Find Customers" Cities</h2>
<hr />
<asp:DropDownList runat="server" ID="CityList" Width="230px">
</asp:DropDownList>
<asp:Button ID="CityButton" runat="server" Text="Get cities..." OnClick="CityButton_Click" />
<hr />
</form>
</div>
</body>
</html>
File: Default.aspx.cs
using System;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Default : System.Web.UI.Page
{
protected void CityButton_Click(object sender, EventArgs e)
{
string connString = ConfigurationManager.ConnectionStrings["NorthwindConnectionString"].ConnectionString;
string cmdText = "SELECT DISTINCT country, city FROM customers";
DataTable data = new DataTable();
SqlDataAdapter adapter = new SqlDataAdapter(cmdText, connString);
adapter.Fill(data);
data.Columns.Add("CityCountry", typeof(string), "city + " ("+ country + ")"");
CityList.DataTextField = "CityCountry";
CityList.DataSource = data;
CityList.DataBind();
}
}</source>

== How to load a DataTable from a DataReader (C#)==



<source lang="csharp">
<%@ Page Language="C#" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<%@ Import Namespace="System.Configuration" %>
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack )
{
SqlConnection MyConnection;
SqlCommand MyCommand;
DataTable MyDataTable;
SqlDataReader MyReader;
SqlParameter CityParam;
MyConnection = new SqlConnection();
MyConnection.ConnectionString = ConfigurationManager.ConnectionStrings["DSN_Northwind"].ConnectionString;
MyCommand = new SqlCommand();
MyCommand.rumandText = " SELECT * FROM CUSTOMERS WHERE CITY = @CITY ";
MyCommand.rumandType = CommandType.Text;
MyCommand.Connection = MyConnection;
CityParam = new SqlParameter();
CityParam.ParameterName = "@CITY";
CityParam.SqlDbType = SqlDbType.VarChar;
CityParam.Size = 15;
CityParam.Direction = ParameterDirection.Input;
CityParam.Value = "London";
MyCommand.Parameters.Add(CityParam);
MyCommand.Connection.Open();
MyReader = MyCommand.ExecuteReader(CommandBehavior.CloseConnection);
MyDataTable = new DataTable();
MyDataTable.Load(MyReader);
gvCustomers.DataSource = MyDataTable;
gvCustomers.DataBind();
MyDataTable.Dispose();
MyCommand.Dispose();
MyConnection.Dispose();
}
}
</script>
<html>
<body>
<form id="form1" runat="server">
<div>
<asp:GridView ID="gvCustomers" runat="server">
</asp:GridView>
</div>
</form>
</body>
</html>
File: Web.config
<configuration>
<connectionStrings>
<add name="DSN_Northwind"
connectionString="Data Source=localhost\SQLEXPRESS;Initial Catalog=Northwind;Integrated Security=True"
providerName="System.Data.SqlClient" />
</connectionStrings>
</configuration></source>

== How to load a DataTable from a DataReader (VB)==



<source lang="csharp">
<%@ Page Language="VB" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<%@ Import Namespace="System.Configuration" %>
<script runat="server">
Protected Sub Page_Load(ByVal sender As Object, _
ByVal e As System.EventArgs)
If Not Page.IsPostBack Then
Dim MyConnection As SqlConnection
Dim MyCommand As SqlCommand
Dim MyDataTable As DataTable
Dim MyReader As SqlDataReader
Dim CityParam As SqlParameter
MyConnection = New SqlConnection()
MyConnection.ConnectionString = ConfigurationManager.ConnectionStrings("DSN_Northwind").ConnectionString
MyCommand = New SqlCommand()
MyCommand.rumandText = " SELECT * FROM CUSTOMERS WHERE CITY = @CITY "
MyCommand.rumandType = CommandType.Text
MyCommand.Connection = MyConnection
CityParam = New SqlParameter()
CityParam.ParameterName = "@CITY"
CityParam.SqlDbType = SqlDbType.VarChar
CityParam.Size = 15
CityParam.Direction = ParameterDirection.Input
CityParam.Value = "London"
MyCommand.Parameters.Add(CityParam)
MyCommand.Connection.Open()
MyReader = MyCommand.ExecuteReader(CommandBehavior.CloseConnection)
MyDataTable = New DataTable()
MyDataTable.Load(MyReader)
gvCustomers.DataSource = MyDataTable
gvCustomers.DataBind()
MyDataTable.Dispose()
MyCommand.Dispose()
MyConnection.Dispose()
End If
End Sub
</script>
<html>
<body>
<form id="form1" runat="server">
<div>
<asp:GridView ID="gvCustomers" runat="server">
</asp:GridView>
</div>
</form>
</body>
</html>
File: Web.config
<configuration>
<connectionStrings>
<add name="DSN_Northwind"
connectionString="Data Source=localhost\SQLEXPRESS;Initial Catalog=Northwind;Integrated Security=True"
providerName="System.Data.SqlClient" />
</connectionStrings>
</configuration></source>

== The DataTable object represents an in-memory database table.==



<source lang="csharp">
<%@ Page Language="C#" %>
<%@ Import Namespace="System.Data" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void Page_Load()
{
DataTable newDataTable = new DataTable();
newDataTable.Columns.Add("Id", typeof(int));
newDataTable.Columns.Add("ProductName", typeof(string));
newDataTable.Columns.Add("ProductPrice", typeof(decimal));
newDataTable.Columns["Id"].AutoIncrement = true;
for (int i = 1; i < 11; i++)
{
DataRow newRow = newDataTable.NewRow();
newRow["ProductName"] = "Product " + i.ToString();
newRow["ProductPrice"] = 12.34m;
newDataTable.Rows.Add(newRow);
}
grdProducts.DataSource = newDataTable;
grdProducts.DataBind();
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Show DataTable Programmatically</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h1>Products</h1>
<asp:GridView
id="grdProducts"
Runat="server" />
</div>
</form>
</body>
</html></source>

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ASP.NET Tutorial/ADO.net Database/DataTable - История изменений

в 15:30, 26 мая 2010

Admin: 1 версия