Beginning Microsoft SQL Server 2008 ... - S3 Tech Training

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System Functions
SQL Server includes a number of “System Functions” as well as more typical functions with the
product. Some of these are used often and are fairly clear right from the beginning in terms of how
to use them. Others, though, are both rarer in use and more cryptic in nature.
In this appendix, we’ll try to clarify the use of most of these functions in a short, concise manner.
Just as an FYI, in prior releases, many system functions were often referred to as “Global Variables.”
This was a misnomer, and Microsoft has striven to fix it over the last few releases — changing
the documentation to refer to them by the more proper “system function” name. Just keep the old
terminology in mind in case any old fogies (such as myself) find themselves referring to them as
Globals.
The T-SQL functions available in SQL Server 2008 fall into the following categories:
❑ Legacy “system” functions
❑ Aggregate functions
❑ Configuration functions
❑ Cryptographic functions
❑ Cursor functions
❑ Date and time functions
❑ Mathematical functions
❑ Metadata functions
❑ Ranking functions
❑ Rowset functions
❑ Security functions
❑ String functions
❑ System functions
❑ Text and image functions