Databases Reference
In-Depth Information
application software, or maybe at the command prompt, but we need to take
things down a level. This functionality is provided by the data API. This deci-
sion lies more with the application developer in most cases, but it's likely that
you might be called on to make recommendations.
There are several options available, depending on your database server,
whether you plan to connect directly or through an application, and the appli-
cation programming language that you select. You may already be familiar with
two APIs: Open Database Connectivity (ODBC) and OLE DB.
ODBC
is an indus-
try standard API that provides connectivity with a wide variety of data sources.
OLE DB
is a Microsoft data access API that also supports a wide variety of
sources. One advantage of OLE DB is that Microsoft has provided versions that
are optimized for specific DBMSs, including OLE DB for Oracle and OLE DB for
SQL Server. Microsoft has also released a new data access technology that is OLE
DB-based and is specific to SQL Server 2005, called
SQL Native Client.
Each of these options provides the same basic functionality. They let a client
(or client application) identify itself to the server and establish a connection.
They let the client prepare commands and pass them to the server for execu-
tion. They also provide various means for receiving a response back from the
server. The differences are in the details.
If you are writing an application and aren't sure as to the final database plat-
form, or perhaps want to leave a level of flexibility built in, it's likely that you
would want to use ODBC or a generic version of OLE DB. If you are using a
Microsoft programming language and want to provide better performance and
more options, then a product-specific version of OLE DB might be more appro-
priate. If you are working with SQL Server 2005 and want to use newly released
features like XML data types, then you need SQL Native Client or the .NET
Framework SQL Client object library.
Meeting Client Interface Requirements
Let's step away from database applications for a moment. Data and database
administrators often find it necessary to access a server directly through man-
agement utilities to make changes or fix problems. However, sitting down at the
server isn't always an option, or even a good idea. You need a way to set up a
client with the necessary connectivity software and management tools.
Luckily, most manufacturers have provided a way to do just that. In the case of
SQL Server, the Setup program gives you the option of installing just the client tools,
which includes all of the necessary drivers, data APIs, and management utilities. You
might be worried that this could be a security risk, but it's not if you've set up secu-
rity properly on your database server and as long as you log off or lock your com-
puter when you leave your desk. Someone trying to hack into the database through
your PC, assuming they could get access to it, would still need login credentials that
provide a high enough level of access to enable them to do any damage.
