Who Should Learn T-SQL?
Sybase and Microsoft first introduced Transact-SQL back in the 1980s as a procedural language for their database server products. Since then, many DB admins have cursed the existence of such a vendor-flavored query language.
Compared to the purely declarative SQL that comes standard with MySQL and Postgres, T-SQL uses a more complex syntax. Meanwhile, Oracle admins realize that Microsoft isn't the only database maker guilty of this transgression.
There are plenty of reasons to learn SQL. What might not be apparent at first glance are the benefits that a more complex procedural database language provides versus a plain vanilla SQL implementation:
Modularity: T-SQL procedures can help a software project adhere to modular programming principles, providing a rapid development environment while reducing the frequency of front-end software updates.
Security: T-SQL allows very complex procedures to be stored on the database server itself, shielding proprietary business transaction knowledge from the client or application server environment.
Efficiency: Data processing workloads can be executed with minimal overhead when transferred from the front-end to the DB server itself.
This extra functionality has some specific applications that can make a Transact compatible server the obvious choice for your organization's database needs. Additionally, using T-SQL on SQL Server (or a Sybase/SAP variant) can make sense from an affordability standpoint when there is a need for a vendor-supported database server.
With this in mind, T-SQL should be of primary importance to a particular subset of IT pros:
Database Admins in a Microsoft, Sybase, or SAP Environment
This is probably the largest of the T-SQL niches.
If your organization is already fully entrenched in the Microsoft ecosystem, it is well worth your time to explore the additional functionality provided by T-SQL compared to the basic data manipulation functions common to all SQL variants.
There also are plenty of organizations who use the legacy Sybase DB server, as well as its current progeny, SAP Adaptive Server Enterprise. All of these database engines benefit from the additional data processing functionality that Transact-SQL provides.
IT pros in the finance industry
Where security is paramount, T-SQL can help keep the details of complex transactions a trade secret. By keeping the processing of these transactions in stored procedures directly on the DB server, it's possible to limit their potential exposure and add an extra layer of protection from hackers.
T-SQL also helps to minimize network traffic. Passing large amounts of sensitive customer data between client and DB server could be viewed as a lapse in security best-practices, creating the possibility of a data breach and potential liability. T-SQL enables more of the sensitive processing to remain securely behind the scenes.
Likewise, from a development standpoint, T-SQL can help keep permissions in check by executing queries without granting permissive DB credentials to client-side developers. This helps to ensure database integrity as well as reduce the avenues of data theft or sabotage by employees or contractors.
Admins for large e-commerce site
High volume e-commerce sites can benefit from the efficiency of T-SQL. User-defined functions and stored procedures can be highly optimized, providing the most efficient queries possible. This results in a more realistic load for front-end web servers, even the most powerful of which can be rapidly overwhelmed when forced to execute complex data processing algorithms within ASP.net, PHP, or ColdFusion.
Webmasters for non-profits and low-budget operations
In Transact-SQL, procedures can be stored, compiled, and optimized once, then called upon whenever necessary. This is far more efficient than executing SQL directly from the web code, where each statement would need to be compiled and optimized every time it is called.
This conservation of server resources means your organization might be able to utilize a 'micro' or 'small' cloud instance, versus a larger instance, significantly reducing operating costs.
By using T-SQL to execute data transaction functions directly on the DB server, updates to data structure can be made without requiring an app update for customers. This results in smaller, more-optimized code on customer devices and less potential for security vulnerabilities.
It's clear that Transact-SQL is more than just a proprietary SQL implementation. It successfully addresses the shortcomings of a declarative language through the addition of constructs common to full procedural languages. If you've dismissed T-SQL in the past, it may be time to explore the many ways it can improve the efficiency, security, and integrity of your data transactions.