Msdn microsoft practices enterpriselibrary

At this point I have created an encryption algorithm key file, but I have not yet told the Enterprise Library Config tool to encrypt the dataConfiguration. To apply the encryption to the block, simply navigate to the Configuration Application Block node and select its dataConfiguration child node.

Then, set the Encrypt attribute to True and save your changes. If you then try to open the dataConfiguration. The DAAB uses the algorithm's key file to decrypt the contents of the file. It might seem odd that the cryptography features I demonstrated work without having to use Enterprise Library's formal Cryptography Application Block.

The reason that the Cryptography Application Block is not needed in this case is that the common library assembly that the blocks refer to contains this limited cryptography feature without all of the overhead of the entire Cryptography Application Block. If, instead of Windows Authentication, you choose to use SQL authentication which means using a specific SQL Server user ID and password combination for each user keep in mind that if the connection string is different for each user, users will not share the same connection pool.

If you use SQL Authentication, consider using a fixed SQL Server account so that the connection string stays the same and you can take advantage of connection pooling. Before you can retrieve or update data you must first establish a connection to a data provider such as SQL Server. In ADO. NET you create a SqlConnection object, passing a connection string to its constructor.

Then you can open the connection and fill a DataSet or retrieve data through a DataReader. If you want to connect to Oracle, you need to create the Oracle-specific connection object. If you want to connect to another data provider, you use its specific connection object or you can use the more generic OleDbConnection. One of the nice features of the DAAB is that you can easily abstract your code from a specific data provider. For example, check out the following code:. This code creates an instance of the Database-derived object, which in this case will be a SqlDatabase object.

One line of code could be modified to make the same CreateDatabase method return an instance of an OracleDatabase object as follows:. The CreateDatabase method of the DatabaseFactory accepts an argument that represents a DatabaseInstance entry in the dataConfiguration. So by changing the database instance, I can change the type of Database object that the DatabaseFactory. CreateDatabase method returns. Rather, I can use their base class, the Database object, thus keeping my code abstracted from data provider specificity.

I can also build my own provider and derive it from the DAAB's abstract Database class you cannot create an instance of it directly because it's abstract. This class inherits and uses most of the methods of the abstract Database class, but it overrides certain properties and methods.

The Database class does not refer to the System. SqlClient namespace, but the SqlDatabase class does. For example, the abstract Database class implements an abstract ParameterToken property that is intended to be overridden in any class that inherits from the Database class.

The SqlDatabase class overrides this property to return the symbol the SQL Server-specific character that precedes parameter names. Another example of an overridden method is the GetConnection method. The DatabaseFactory class is sealed, so it cannot be inherited. Its constructor is private, so the DatabaseFactory cannot be directly instantiated either. This allows me to call the static CreateDatabase method without allowing me to create an instance of the class itself.

When you call the CreateDatabase method and pass it a database instance name, the DAAB uses reflection to figure out what specific type of Database object to create. This method basically takes an instance of the Type class, which represents the Database-derived class you want to create.

It gets the constructor of the class by using the following line of code through reflection:. Once it has the constructor, it then tries to invoke the constructor by using reflection once again:. In this scenario, the createdObject variable then represents the instance of the SqlDatabase object. There is quite a bit of code surrounding this whole process, but the abstract classes, the classes that derive from them and override their methods and properties, and reflection are at the heart of the Database Factory pattern.

Unless you are truly intrigued by the inner workings of the DAAB, you don't need to delve deep into its code. Not for VB6 questions. Sign in to vote. Finally which edition of Visual Studio has the most functionality please? What is the difference between the various editions of Visual Studio please? I don't need to know about the Express editions. Regards, John. Wednesday, October 31, PM. John Oliver, 1. Friday, November 2, AM.

I'm trying to use database role to access the database; step - 1: Open the database connection using database role step - 2: Execute the stored proc using the above connection My question, is that possible to use the above one using enterprise library DATA? Wednesday, November 14, PM. Thank You Brunu Thursday, November 29, AM. Stand-alone download managers also are available, including the Microsoft Download Manager. The Microsoft Download Manager solves these potential problems.

It gives you the ability to download multiple files at one time and download large files quickly and reliably. It also allows you to suspend active downloads and resume downloads that have failed. Microsoft Download Manager is free and available for download now. Warning: This site requires the use of scripts, which your browser does not currently allow. See how to enable scripts. Download Microsoft Enterprise Library 5. Microsoft Enterprise Library 5.

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