Pro LINQ in C Sharp
apparent that one of the more troublesome areas still remaining for developers is that of accessing data
from different data sources. In particular, database access and XML manipulation are often
cumbersome at best and problematic at worst.
The database problems are numerous. First, there is the issue that we cannot programmatically
interact with a database at the native language level. This means syntax errors often go undetected until
runtime. Incorrectly referenced database fields are not detected either. This can be disastrous, especially
if this occurs during the execution of error-handling code. Nothing is more frustrating than having an
entire error-handling mechanism fail because of syntactically invalid code that has never been tested.
Sometimes this is unavoidable because of unanticipated error behavior. Having database code that is
not validated at compile time can certainly lead to this problem. A second problem is the nuisance caused by the differing data types utilized by a particular data
domain, such as database or XML data types versus the native language in which the program is written.
In particular, dates and times can be quite a hassle.
XML parsing, iterating, and manipulation can be quite tedious. Often an XML fragment is all that is
desired, but because of the W3C DOM XML API, an XmlDocument must be created just to perform
various operations on the XML fragment.
Rather than just add more classes and methods to address these deficiencies in a piecemeal fashion,
the development team at Microsoft decided to go one step further by abstracting the fundamentals of
data query from these particular data domains. The result was LINQ. LINQ is Microsoft’s technology to
provide a language-level support mechanism for querying data of all types. These types include inmemory
arrays and collections, databases, XML documents, and more.
