T-SQL System Variables and Functions
The terms “variable” and “function” are often used interchangeably. SQL Server Books Online documents some variables as though they were functions. However, it is important to note that variables are used in expressions to obtain a value, whereas functions process specific business logic and may return a value. Many functions accept input arguments.
This appendix applies to SQL Server 2008, 2008 R2, and 2012. It is a reference of common T-SQL objects provided as a convenient guide to many functions and variables that may be useful in report queries. It is by no means meant to be a comprehensive reference. For complete details and examples of usage, consult Books Online.
The system-supplied global variables are organized into the following categories:
|@@DATEFIRST||tinyint||The system setting for the first day of the week: 1 = Monday 2 = Tuesday 3 = Wednesday 4 = Thursday 5 = Friday 6 = Saturday 7 = Sunday The U.S. default is 7.|
|@@DBTS||varbinary||The last assigned unique TimeStamp value.|
|@@LANGID||smallint||The current language ID for the server:
0 = U.S. English
1 = German
2 = French
and so on.
|@@LANGUAGE||nvarchar||The current language string for the server. Returns the language name in the native language form (us_english, Deutsch, Français, Dansk, Español, Italiano, and so on).|