Disadvantages of the SqlDataSource in ASP

Disadvantages of the SqlDataSource
As you have seen, when you use the SqlDataSource control, you can often avoid writing any data access
code. However, you also sacrifice a fair bit of flexibility. Here are the most significant disadvantages:
❑ Data access logic embedded in the page:To create a SqlDataSource control, you need to
hard-code the SQL statements in your web page. This means that you cannot fine-tune your
query without modifying your web page. In an enterprise application, this limitation is not
acceptable, as it is common to revise the queries after the application is deployed in response to
profiling, indexes, and expected loads. You can improve this situation a fair bit by restricting
your use of the SqlDataSource to stored procedures. However, in a large-scale web applica-
tion, the data access code will be maintained, tested, and refined separately from the business
logic (and it may even be coded by different developers). SqlDataSource just does not give
you that level of flexibility.
❑ Maintenance in large applications: Every page that accesses the database needs its own set of
SqlDataSource controls. This can turn into a maintenance nightmare, particularly if you have
several pages using the same query (each of which requires a duplicate instance of the
SqlDataSource ). In a component-based application, you will use a higher-level model. The
web pages will communicate with a data access library, which will contain all the database
details.
❑ Inapplicability to other data tasks: The SqlDataSource does not properly represent some
types of tasks. The SqlDataSource is intended for data display and data-editing scenarios.
However, this model breaks down if you need to connect to the database and perform another
task, such as placing a shipment request into an order pipeline or logging an event. In these sit-
uations, you will need custom database code. It will simplify your application if you have a sin-
gle database library that encapsulates these tasks along with data retrieval and updating
operations.
Although the SqlDataSource control is powerful, there are a number of other data source controls that
might better suit your specific data access scenario. One such control is XmlDataSource control, which
is the topic of focus in the next section.