Introduction
Most developers, as they continue to produce software products, start to build libraries of reusable code. Much of it is the mundane tasks that are associated with standard software development.
That’s why Microsoft started sharing some of their proven code with the development community back in 2005. Since that initial release there have been several versions that have continued keeping up with new technologies and providing a much quicker development time with the most current version being 4.0 that was released on May of this year.
This series will delve into common uses for each of these “blocks” of code. For this series, version 3.1 will be used along with SQL 2005 Express with the AdventureWorks database.
Implementation
Start a new project, it can be a Windows or web application. Go ahead and add a reference to the data access application block.
Repeat the step to add a reference to the shared Common and Configuration dll as well. They will come into play later in the article.
On the designer for the Default.aspx drag a GridView control onto the work area. Before we jump right into the DAAB, let’s take a look at what would usually be done when accessing data from the database.
// Create a connection to the datbase string conn = "Server=(local);Database=AdventureWorks;IntegratedSecurity=True;"; // Create the query to be executed string query = "select * from Production.Product where ProductID = 1"; // Create the connection object then open the connection SqlConnection sqlConn = new SqlConnection(conn); sqlConn.Open(); // Create the command object then set the appropriate commamd type SqlCommand sqlCmd = new SqlCommand(query, sqlConn); sqlCmd.CommandType = CommandType.Text; // Set the data source of the grid to the the ExecuteReader method GridView1.DataSource = sqlCmd.ExecuteReader(); GridView1.DataBind(); // Make sure to close the connection objConn.Close();
Now to achieve the same results using the DAAB, so first open up the web.config and add some connection information. I should look something like this:
<connectionStrings> <add name="Production" connectionString="Server=zturnbow\sqlexpress;Database=AdventureWorks;Integrated Security=True" providerName="System.Data.SqlClient" /> </connectionStrings>
Go back to the code behind and add the following using statements:
using Microsoft.Practices.EnterpriseLibrary.Data; using Microsoft.Practices.EnterpriseLibrary.Data.Sql; using Microsoft.Practices.EnterpriseLibrary.Configuration; using Microsoft.Practices.EnterpriseLibrary.Common;
Since everything is setup now, let’s write some code. The first thing is to create a database reference. It will need to be placed after the partial class declaration in the code behind. It will look like this:
Database db = DatabaseFactory.CreateDatabase("Production");
Add code to create the SQL query string and access the database to retrieve the data and bind it to the grid.
// Create the SQL query string strSql = "select * from Production.Product where ProductID = 1"; // Set the grid data source to the SQL helper class ExecuteReader method by supplying // the proper information GridView1.DataSource = db.ExecuteReader(CommandType.Text, strSql); GridView1.DataBind();
It is simple to see that it requires less typing to get the same results. Many people think there is not much benefit but when doing development, the more typing involved, the more likely there are going to be mistakes.
The more mistakes (bugs), the more it takes time to finish a project.
What have we learned?
How to add a reference to a dll in a project.
How use the web.config file to hold database connection strings.
How to use the Enterprise Library Configuration Application Block to configure a database connection from the web.config
How to use the Enterprise Library Data Access Application Block to retrieve data from a database.
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