Wednesday, November 05, 2014

Introduction to TSQL

SQL is the lingua franca of the database world. Most modern DBMSs use some type of SQL dialect as their primary query language, including SQL Server. You can use SQL to create or destroy objects on the database  server such as tables and to do things with those objects, such as put data into them or query them for that  data. No single vendor owns SQL, and each is free to tailor the language to better satisfy its own customer base. Despite this latitude, there is a multilateral agreement against which each implementation is measured.
It's commonly referred to as the ANSI/ISO SQL standard and is governed by the National Committee on Information Technology Standards (NCITSH2). This standard is actually several standards—each named after the year in which it was adopted. Each standard builds on the ones before it, introducing new features, refining language syntax, and so on. The 1992 version of the standard—commonly referred to as SQL-92—is probably the most popular of these and is definitely the most widely adopted by DBMS vendors. As with other languages, vendor implementations of SQL are rated according to their level of compliance with the ANSI/ISO standard. Most vendors are compliant with at least the entry-level SQL-92 specification, though some go further.
Transact-SQL is Microsoft SQL Server's implementation of the language. It is largely SQL-92 compliant, so if you're familiar with another vendor's flavor of SQL, you'll probably feel right at home with Transact-SQL. Since helping you to become fluent in Transact-SQL and an important step in becoming a skilled SQL Server practitioner, it's instructive to begin with a brief tour of language fundamentals.

Frequently, the would-be SQL practitioner is forced to run a gauntlet of syntax sinkholes and query quicksand while lugging a ten-volume set on database design and performance and tuning on her back. It's easy to get disoriented in such a situation, to become inundated with nonessential information—to get bogged down in the details. Add to this the obligatory dose of relational database theory, and the SQL neophyte is ready to leave summer camp early.

TSQL Tutorial.........

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