Professional SQL Server™ 2005 Programming

3.7. Summary

T-SQL is SQL Server's own brand of ANSI SQL or Structured Query Language. T-SQL is entry-level ANSI 92 compliant, but it also has a number of its own extensions to the language — we'llsee more of those in later chapters.

Even though, for backward compatibility, SQL Server has a number of different syntax choicesthat are effectively the same, wherever possible, you ought to use the ANSI form. Where there aredifferent choices available, I will usually show you all of the choices, but again, stick with the ANSI version wherever possible. This is particularly important for situations where you think yourback end — or database server — might change at some point. Your ANSI code will, more than likely, runon the new database server — however, code that is only T-SQL definitely will not. The alternative INNER join syntax will work on most SQL products today, but the OUTER join syntax will not. FULL joins are often not supported in other DBMSs at all.

In our next chapter, we'll be reviewing how to CREATE and ALTER the tables that we want to select from. In this area, we'll see there are far fewer "nonstandard" choices.