Linglom's blog » Windows

Accessing SQL Server on ASP.NET Web Application using ADO.NET

linglom — Wed, 14 Apr 2010 06:28:21 +0000

ADO.NET is a set of components that can be used to access data and data services. The objects of ADO.NET that will be used in this post are:

Connection: Provides a connection used to communicate with the data source.
DataAdapter: A bridge used to transfer data between a Data source and a DataSet object.
DataSet: Stores query result from DataAdapter.

On this post, you will see how to develop an ASP.NET web application that query data from SQL Server 2005 and display the result on a GridView object. I have provided both VB.NET and C# programming languages.

Step-by-step

Create a connection string in web.config. I decide to put the connection string in web.config so that I can re-use the connection string in other web form.
```
<connectionstrings>
		<add name="Northwind" 
       connectionString="Data Source=BKKSQL001\INSTANCE01;
       Initial Catalog=Northwind;
       Integrated Security=True" 
      providerName="System.Data.SqlClient"/>
connectionstrings>
```
Attributes explanation:
- name: A connection string name.
- connectionString: A connection string which is used to connect to a database. On this example, it connects to Northwind database on BKKSQL001\INSTANCE01.
- providerName: A provider name that is used.

On a Web Form, imports some namespaces which are required for working with SQL Server. System.Web.Configuration is use to read values from web.config.

'Visual Basic
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.Configuration

//C#
using System.Data;
using System.Data.SqlClient;
using System.Web.Configuration;

Use a GridView object to display the query result. Set the name of GridView to “gridView1“. Copy and paste the code below to Page_Load method.

'Visual Basic
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
 
        Dim connStr As String = WebConfigurationManager.ConnectionStrings("Northwind").ConnectionString
        Dim conn As New SqlConnection(connStr)
        conn.Open()
 
        Dim sqlProducts As String = "SELECT ProductID, ProductName, UnitPrice FROM Products"
 
        Dim da As New SqlDataAdapter(sqlProducts, conn)
        Dim ds As New DataSet()
        da.Fill(ds, "Products")
 
        gridView1.DataSource = ds.Tables("Products")
        gridView1.Databind()
End Sub

//C#
protected void Page_Load(object sender, EventArgs e)
    {
        string connStr = WebConfigurationManager.ConnectionStrings["Northwind"].ConnectionString;
        SqlConnection conn = new SqlConnection(connStr);
        conn.Open();
 
        string sqlProducts = "SELECT ProductID, ProductName, UnitPrice FROM Products";
 
        SqlDataAdapter da = new SqlDataAdapter(sqlProducts, conn);
        DataSet ds = new DataSet();
        da.Fill(ds, "Products");
 
        gridView1.DataSource = ds.Tables["Products"];
        gridView1.DataBind();
    }

Code Explanation:

Line 4-6: Get a connection string value from web.config. Then, open a connection using the connection string to a SQL Server.
Line 8: Create a variable “sqlProducts” which stores SQL query from Products table.
Line 10-12: Create a SqlDataAdapter object “da” to execute the query. Then, create a DataSet object “ds” to hold the result from object “da” and set name to “Products“.
Line 14-15: Display data from object “ds” on a GridView object “gridView1“.

Run the project. You will see the result as figure below.

Accessing SQL Server on ASP.NET Web Application using SqlDataSource Web Control, Part 2: UPDATE Data

linglom — Fri, 02 Apr 2010 03:32:54 +0000

Accessing SQL Server on ASP.NET Web Application using SqlDataSource Web Control, Part 2: UPDATE Data

From part 1: SELECT Data, you see how to query data from SQL Server 2005 to display on a GridView object using SqlDataSource web control. But the data is read-only, you cannot modify any data on a GridView. So now you will see how to modify data on the GridView which will update back on the database.

Step-by-step

Note: This example is continue from part 1: SELECT Data.

On SqlDataSource1, click on Configure Data Source.
On Choose Your Data Connection, click Next.
On Configure Select Statement, change the option from Specify columns from a table or view to Specify a custom SQL statement or stored procedure. Click Next.
On Define Custom Statements or Stored Procedures, you see 4 tabs which are SELECT, UPDATE, INSERT and DELETE. Here you can define custom SQL statements for each SQL operations. On SELECT tab, enter the SQL statement as below:
```
SELECT [ProductID], [ProductName], [UnitPrice] FROM [Products]
```

Click on UPDATE tab, enter the SQL statement below and click Next.

UPDATE Products SET ProductName = @ProductName, UnitPrice = @UnitPrice
WHERE [ProductID] = @ProductID

On Test Query, Click Finish.
On GridView1, click Edit Columns.
On Fields, select Command Fields -> Edit, Update, Cancel on Available fields and click Add. Then, move the field Edit, Update, Cancel to the top by click on up arrow button. Next, click OK.
On GridView1, check Enable Editing to allow edit data on the Grid View.
Build and run the project. You see the Edit column in front of each row. Click Edit to edit the row.
You can modify the value of product name and unit price of the row which also update back on the database, too.

Accessing SQL Server on ASP.NET Web Application using SqlDataSource Web Control, Part 1: SELECT Data

linglom — Fri, 26 Mar 2010 04:40:26 +0000

Accessing SQL Server on ASP.NET Web Application using SqlDataSource Web Control, Part 1: SELECT Data

On this post, you will see how to develop an ASP.NET web application that query data from SQL Server 2005 and display the result on a GridView object using SqlDataSource web control so you don’t have to write any code!

Step-by-step-

Drag a SqlDataSource object from Toolbox to a Web Form.
On SqlDataSource1 object, click Configure Data Source.
On Choose Your Data Connection, click New Connection.
On Add Connection, select Data Source as Microsoft SQL Server (SqlClient). Then, type the Server name of the SQL Server and select a database. On this example, the server is BKKSQL001\INSTANCE01 and Northwind is the database.
On Save the Connection String to the Application Configuration File, click Next to continue.
On Configure the Select Statement, select Specify columns from table or view and select Products table. Then, check ProductID, ProductName and UnitPrice columns. Click Next.
On Test Query, you can click on Test Query button to verify the query result. Then, click Finish.
Drag a GridView object from Toolbox to the Web Form. Then, choose the Data Source to the one that you have just created.
Build and run the project. You will see the result as the figure below.

Getting started with Microsoft ISA Server 2006, Part 12: Block Windows Live Messenger

linglom — Wed, 24 Feb 2010 02:28:32 +0000

This article is one of the series of Getting started with Microsoft ISA Server 2006. You can see the index of this series at Getting started with Microsoft ISA Server 2006, Part 1: Introduction.

Block Windows Live Messenger

From Part 11: HTTP Filtering, you learn about HTTP filtering concept. Now let’s apply it with a real world example, Windows Live Messenger. On this post, I show you how to block Windows Live Messenger on ISA Server 2006.

Windows Live Messenger is a popular instant messaging application, many people using it regularly. But sometimes, people use it at work place and unintentionally receive a file containing virus. Then, they execute it, so the virus spread on the network. Therefore, it is a task of an IT staff to secure the system and prevent this issue. The best and effective solution is to enforce strictly firewall policy. But sometimes, you cannot do that. For example, users on research department want access to any websites (HTTP) because they do not know what websites they want to access until they need. Then, you have to create an access rule to allow HTTP to from Internal to External for these users. Now they can use Windows Live Messenger because Windows Live Messenger communicates with its servers through either of these ports:

MSN Messenger protocol (TCP: 1863).
HTTP protocol (TCP: 80).

If you block only MSN Messenger protocol, users still can use Windows Live Messenger through HTTP protocol. Now what should you do? Block HTTP protocol? Doing that will also block users to access websites so you cannot do that. Here it comes, HTTP filtering. You can block only Windows Live Messenger on ISA Server without blocking the HTTP protocol if you know the signature. HTTP header is also the signature.

So what is the signature of Windows Live Messenger? I have sniffed HTTP packets while I signing to Windows Live Messenger. Here are the signature and protocol port of Windows Live Messenger:

The client communicates with the server of Windows Live Messenger using TCP outbound port 1863.
While the client requesting information from the server (request header), one signature of it is User-Agent: Windows Live Messenger.

Now I show you how to configure to block Windows Live Messenger on ISA Server 2006.

Step-by-step

Create an access rule to block TCP outbound port 1863. ISA Server 2006 already has pre-defined this port as MSN Messenger protocol. I am not going to show detail steps on creating an access rule. You can review them at Part 7: Create DNS Lookup Rule and Part 8: Create Web Access Rule.
- Rule Name: Block Windows Live Messenger
- Action: Deny
- Protocol: MSN Messenger
- From: Internal
- To: External
- Condition: All Users
Next, configure HTTP filtering to block the signature of Windows Live Messenger. Right click on “Allow HTTP, HTTPS for Linglom” and select Configure HTTP.
Note: This menu option available on an access rule that contains HTTP protocol only.
On Configure HTTP policy for rule, click on Signatures tab and click Add.
On Signature, enter these information below to block Windows Live Messenger and then click OK.
- Name: Blocks Windows Live Messenger or any name as you want.
- Search in: Request headers
- HTTP header: User-Agent:
- Signature: Windows Live Messenger
Note: Don’t forget semi-colon (:) after User-Agent text.
Back to Configure HTTP policy for rule, you see the signature has been created for this rule. You also can disable the signature by un-check it. On this example, leave it as checked to enable the signature. Click OK.
Don’t forget to click Apply to update the configuration.
Let’s try to sign in Windows Live Messenger on the client computer, you see that I cannot sign in any more.

Summary

Now You have reach the end of Getting started with Microsoft ISA Server 2006 series. This series contains 12 parts: it gives you an introduction of ISA Server 2006, how to install and configure ISA Server 2006 on simple environment, how to create an access rule, and how to use some useful features on ISA Server 2006. I hope you get what you want on this series. If you have any comment or suggestion, feel free to leave it below.

Getting started with Microsoft ISA Server 2006, Part 11: HTTP Filtering

linglom — Wed, 17 Feb 2010 02:58:03 +0000

This article is one of the series of Getting started with Microsoft ISA Server 2006. You can see the index of this series at Getting started with Microsoft ISA Server 2006, Part 1: Introduction.

HTTP Filtering

From Part 10: Logging, you learn how to configure and use logging on ISA Server 2006. Now, you will learn about HTTP filtering.

Have you ever want to block users using MSN or Yahoo messenger, or deny them to using free email services, or block them to post anything on web boards, or block them to use bit-torrent to download files? This post will answer these questions with Microsoft ISA Server 2006.

HTTP traffic is a data packet using HTTP protocol on the network which is used by most applications. On each packet of HTTP traffic, there is a header which contains information about server and client that are communicating each other at the time. These header information are such as:

Request Methods. For example, GET, POST, CONNECT.
User-Agent, such as Mozilla/4.0, Mozilla/5.0, Firefox
Content-Type. The mime type of the body of the request, such as application/x-www-form-urlencoded, application/xml, image/jpeg, text/xml.
Host. The domain name of the server, for example, www.bing.com, www.linglom.com.

For more information about HTTP, see these links from wiki.org:

So why learn about these HTTP headers? You can use these HTTP headers information to block or allow specific application on ISA Server 2006. Still not get it? Let’s see some examples of real HTTP traffic.

You can use some sniffer program to capture data packets that pass in/out through a network interface card on a computer. On this example, I use Ethereal. I install it on the same server as ISA Server 2006 but you can install and test on any computer as you want. Then, I start capturing packets on the network interface card that connects to the Internet and browse to http://www.bing.com using Internet Explorer.

After that, I see these HTTP traffics on ethereal. First, My computer sends a HTTP request to the web server (www.bing.com).
Detail: Request Method is GET. User-Agent is Mozilla/4.0 (compatible: MSIE 6.0). HOST is www.bing.com.

Second, the web server has send HTTP response back to the client. The response packet looks similar as the figure below.
Detail: Response Code is 200 (OK). Content-Type is text/html.

What’s Next?

Now you learn some concepts about HTTP and its header. Next, I will show how to use these information to block Windows Live Messenger on ISA Server 2006. See Part 12: Block Windows Live Messenger.

Getting started with Microsoft ISA Server 2006, Part 10: Logging

linglom — Fri, 05 Feb 2010 09:04:25 +0000

This article is one of the series of Getting started with Microsoft ISA Server 2006. You can see the index of this series at Getting started with Microsoft ISA Server 2006, Part 1: Introduction.

Logging

From Part 9: Client Configuration, you learn how to configure a client computer. On this post, I will show how to use logging to observe usage which is a feature on ISA Server 2006 which keeps track any usage on ISA Server 2006.

When there is a communication between networks (Internal, External, Localhost, etc.) on the ISA Server, it will generate log. The log shows the log time, source IP address, destination IP address and port, action, rule applied to, etc. You can configure what fields that you want to log. There are three log storage formats supported on ISA Server 2006: MSDE database, SQL database and file.

The benefits of logging:

Track usage on certain users, groups.
Troubleshoot issues on the ISA Server.
Keep as Internet access log. In some countries, it is require to keep the Internet access log in order to comply with the law.

Step-by-step

Logging Configuration

Actually, there is no need to configure logging on ISA Server 2006 because the configuration works great on default settings already.

Open Logging by expand Arrays -> BKKISA001 -> Monitoring. Click on Logging tab.
To configure firewall logging, select Tasks -> Configure Firewall Logging.
Note: You also can configure web proxy logging by click on Configure Web Proxy Logging. The configuration is the same as firewall logging so I will not repeat it.
On Firewall Logging Properties, you can choose to keep log on MSDE, SQL Server or a file. The default configuration is MSDE database and the default location is C:\Program Files\Microsoft ISA Server\ISALogs. Let’s click on Options next to MSDE database to see what can be configured for MSDE database.
On Options, you see that you can change location to store the log files and the log file storage limitation. You can limit the size of log files, maintain disk space by deleting the older log files or discard new entries and whether you want to delete log files after period of time.
Back to Firewall Logging Properties, there is another tab, Fields. Here you can customize which fields you want to keep or discard on log files. Normally, you don’t have to modify these configuration. It works perfect by default.

Observe Logging

On Logging, click on Start Query.
Generate some traffic by access the Internet on the client computer. Open web browser and browse to www.google.com.
Now you see some logs on the ISA Server 2006.
You can filter logging on ISA Server 2006 by click on Edit Filter.
On Edit Filter, modify columns and conditions as you want. Then, click Start Query.
This is an example of the filtered logs on ISA Server 2006.

What’s Next?

Now you learn how to observe logging on ISA Server 2006. It is a useful feature which allow you to troubleshoot issues most of the time. Next, I will show more advance topic, HTTP filtering. See Part 11: HTTP Filtering.

No related posts.

[Solved] ActiveX component can’t create object: ‘SQLDMO.SQLServer’ on SQL Server 2008

linglom — Wed, 13 Jan 2010 04:22:38 +0000

Problem

If you execute a vb script which use SQL-DMO on SQL Server 2008, you will notice that the script doesn’t work at all.

You will see the error message as similar to this one when you execute the vb script:

Error: ActiveX component can’t create object: ‘SQLDMO.SQLServer’
Code: 800A01AD
Source: Microsoft VBScript runtime error

Cause

This is because SQLDMO is deprecated since SQL Server 2005. But SQLDMO is installed on SQL Server 2005 by default so you can run a vb script which uses SQLDMO without any error on SQL Server 2005. On SQL Server 2008, SQLDMO is not installed by default . If you want to use SQLDMO, you have to install it manually.

Solution

To use SQL-DMO on SQL Server 2008, you need to download and install Microsoft SQL Server 2005 Backward Compatibility Components to solve the problem. You can go to Microsoft Download Center and search for “Microsoft SQL Server 2008 Feature Pack” and sort by Release Date to find the latest version. Or you can download at Linglom’s Download Page.

Step-by-step

Download Microsoft SQL Server 2005 Backward Compatibility Components. Next, execute the setup file.
On Welcome to the Install Wizard for Microsoft SQL Server 2005 Backward compatibility Setup, click Next.
On License Agreement, select ‘I accept the terms in the license agreement‘. Then, click Next.
On Registration Information, enter your personal information. Then, click Next.
On Feature Selection, ensure that SQL Distributed Management Objects is selected. Then, click Next.
Note: SQL-DMO is the feature that is require to run a vb script that uses DMO.
On Ready to Install the Program, click Install.
Installing Microsoft SQL Server 2005 Backward compatibility.
On Completing the Microsoft SQL Server 2005 Backward compatibility Setup, click Finish. Now try to run vb script again, the problem should be gone!

Reference

Where the Heck is DMO?

No related posts.

Getting started with Microsoft ISA Server 2006, Part 9: Client Configuration

linglom — Wed, 25 Nov 2009 08:21:30 +0000

This article is one of the series of Getting started with Microsoft ISA Server 2006. You can see the index of this series at Getting started with Microsoft ISA Server 2006, Part 1: Introduction.

Client Configuration

From Part 8: Create Sample Access Rule, you have created an access rule on ISA Server 2006. Now, it is time to configure the client computer. There are three types of client that you can choose: SecureNAT, Firewall client and Web Proxy. Each type has a different features, see the table below for the comparison.

On this example, I configure the client computer as firewall client type. But you will see how to configure all types of client.

Client Types

The table below compares the ISA Server clients.

Feature Client types	SecureNAT client	Firewall client	Web Proxy client
Installation required	No, but some network configuration changes may be required	Yes	No, Web browser configuration required
Operating system support	Any operating system that supports Transmission Control Protocol/Internet Protocol (TCP/IP)	Only Windows platforms	All platforms, but by way of Web application
Protocol support	Application filters for multiple connection protocols required	All Winsock applications	Hypertext Transfer Protocol (HTTP), Secure HTTP (HTTPS), File Transfer Protocol (FTP), and Gopher
User-level authentication	No	Yes	Yes
Server applications	No configuration or installation required	Configuration file required	Not applicable

SecureNAT client

To configure client as SecureNAT client type, set the default gateway of the network interface card on client to the ISA Server.
If you are using DHCP, you can configure by add Router scope option to the ISA Server.

Firewall client

Download Firewall Client for ISA Server from Microsoft.
Install Microsoft Firewall Client on the client computer.
On ISA Server Computer Selection, select Connect to this ISA Server computer and type the ISA Server host name.
After the installation completes, you will see the firewall client’s icon on the task bar.
You can view and modify configuration by double-click on the icon and select Settings tab. Also, you can click on Apply Default Settings Now for other users on this computer can use this configuration.

Web Proxy client

Open your web browser. On this example, I use Internet Explorer.
On Menu bar, Click on Tools -> Internet Options.
On Internet Options, Select Connections tab and click on LAN settings.
On Local Area Network (LAN) Settings, check the box Use a proxy server for your LAN and type the ISA Server address and port.

What’s Next

Now I have done the basic configuration on both ISA Server 2006 and the client computer. Next, it is time to test accessing the Internet from the client through the ISA Server. See Part 10: Logging.

Getting started with Microsoft ISA Server 2006, Part 8: Create Web Access Rule

linglom — Tue, 17 Nov 2009 03:06:51 +0000

This article is one of the series of Getting started with Microsoft ISA Server 2006. You can see the index of this series at Getting started with Microsoft ISA Server 2006, Part 1: Introduction.

Create Firewall Policy Rule

From Part 7: Create DNS Lookup Rule, you have create an access rule to allow DNS look up from the internal network to the external DNS addresses. But you do not have any web access rule for users. So now, I will show how to create an access rule on ISA Server 2006 to allow HTTP and HTTPS protocols for a user to access the Internet.

Step-by-step

On ISA Server Management, open Firewall Policy by expand Arrays -> BKKISA001 -> Firewall Policy (BKKISA001).
On Firewall Policy, select Tasks and click on Create Access Rule.
On Welcome to the New Access Rule Wizard, type a name for the access rule. On this example, I type “Allow HTTP, HTTPS for Linglom” and click Next.
On Rule Action, select Allow and click Next.
On Protocols, you have to choose which protocols will be applied to this rule.
- Select Selected protocols and click Add.
- On Add Protocols, expand Common Protocols and double-click on HTTP and HTTPS. Then, click Close and click Next to continue.
On Access Rule Sources, select the source network for this rule.
- Click Add.
- On Add Network Entities, expand Network and double-click on Internal. Click Close and click Next to continue.
On Access Rule Destinations, do the same as the previous step but select External network as a destination.
On User Sets, you have to select which users and groups are applied to this access rule. On this example, I want this rule apply to only a domain user account – linglom.
- Remove All Users by click on Remove and add a new User Sets by click Add.
- On Add Users, you see existing user sets available. There is no user set that I want so I will create a new one. Click New.
- On Welcome to the New User Set Wizard, type the name of a new user set that you want and click Next.
- On Users, click Add -> Windows users and groups.
- On Select Users or Groups, select the users or groups that you want to add to this new user set. On this example, I select the domain user – linglom. Then, click OK.
- You see that the user has been added to a new user set. Click Next.
- On Completing the New User Set Wizard, click Finish.
- A new user set is created. The, select on it and click Add to add the new user set to this rule.
- Now the user set is added to the rule. So this rule will be apply to only this user – Linglom. Click Next.
On Completing the New Access Rule Wizard, click Finish.
Don’t forget to save the changes that you have made by click on Apply at the top.
The changes have been saved. Click OK.
Now you see the rule that you have created.

What’s Next

You have some access rules on ISA Server 2006. That’s it for the basic configuration on the sever. Next, I will start configure client to access the Internet through ISA Server 2006. See Part 9: Client Configuration.

Getting started with Microsoft ISA Server 2006, Part 7: Create DNS Lookup Rule

linglom — Mon, 09 Nov 2009 08:14:12 +0000

This article is one of the series of Getting started with Microsoft ISA Server 2006. You can see the index of this series at Getting started with Microsoft ISA Server 2006, Part 1: Introduction.

Create DNS Lookup Rule

From Part 6: Configure Network Layout, you have configured network environment of the ISA Server 2006. Now let’s create some access rules on ISA Server 2006.

On this example, I have internal and external DNS servers as I have shown the network diagram in Part 2: Environment Setup. The internal DNS server should work fine since it is on the same network with clients – the Internal network. But the external DNS servers (or my ISP’s DNS servers) are on the external network. And currently, ISA Server 2006 blocks all network access so clients from the internal network cannot request any DNS look up from the external DNS servers. This would be a problem if some clients want to use the Internet. Therefore, I will create an access rule to allow DNS look up for clients on the internal network to the external DNS servers. The external DNS servers are 203.144.255.71 and 203.144.255.72.

Step-by-step

On ISA Server Management, open Firewall Policy by expand Arrays -> BKKISA001 -> Firewall Policy (BKKISA001).
Create a new access rule by click on Tasks tab -> Create Access Rule.
On Welcome to the New Access Rule Wizard, type the access rule name. On this example, I type “Allow DNS Lookup” and click Next.
On Rule Action, you can select allow or deny on this rule. Select Allow and click Next.
On Protocols, you can select the protocols this rule applied to.
- Choose Select protocols from a drop down menu and click Add.
- On Add Protocols, expand Common Protocols and double-click on DNS. Click Close.
- Back to Protocols, now the DNS protocol is added to the rule. Click Next.
On Access Rule Sources, you can specify source networks for this rule.
- Click Add.
- On Add Network Entities, expand Networks and double-click on Internal. Click Close.
- Back to Access Rule Sources, now the Internal network is added as access rule source. Click Next.
On Access Rule Destination, you can specify destination networks for this rule.
- Click Add.
- On Add Network Entities, click on New -> Address Range.
- On New Address Range Rule Element, type the name and specify the IP address range. On this example, I name it as “External DNS Addresses” and the IP address range is 203.144.255.71 to 203.144.255.72. Click OK.
- Back to Add Network Entities, there is a new address range that I have just created so double-click on it to add to the rule and click Close.
- Back to Access Rule Destination, now the “External DNS Addresses” is added to the rule as access rule destination. Click Next.
On User Sets, you can specify the user sets for the rule. On this example, I leave it as All Users and click Next.
On Completing the New Access Rule Wizard, click Finish.
To save changes that you have made, you must click on Apply.
On Saving Configuration Changes, click OK.
Now you have completed create an access rule to allow DNS look up from internal network to the external DNS server.

What’s Next?

You have created your first access rule for DNS look up. Now clients will be able to resolve name on the Internet. But there is no access rule for Internet access yet. So next, I will create another access rule for clients to access the Internet. See Part 8: Create Web Access Rule.