Microsoft® SQL Server® 2012 Bible

405

Chapter 16: Programming with T-SQL

16

System functions can’t be created. There’s a fi xed set of system functions, all beginning

with two @ signs. (The more signifi cant ones are listed in Table 16-1.) The most commonly

used global variables are @@NestLevel, @@Rowcount, @@ServerName, and @@Version.

The system functions are being replaced by DMO information.

TABLE 16 -1 System Functions

System Function Returns Scope

@@DateFirst The day of the week currently set as the fi rst day of

the week; 1 represents Monday, 2 represents

Tuesday, and so on. For example, if Sunday is the

fi rst day of the week, @@DateFirst returns a 7.

Connection

@@Error The error value for the last T-SQL statement

executed.

Connection

@@Fetch_Status The row status from the last cursor fetch

command.

Connection

@@LangID The language ID used by the current connection. Connection

@@Language The language, by name, used by the current

connection.

Connection

@@Lock_TimeOut The lock timeout setting for the current

connection.

Connection

@@Nestlevel Current number of nested stored procedures. Connection

@@ProcID The stored procedure identifi er for the current

stored procedure. This can be used with sys

.objects to determine the name of the current

stored procedure, as follows:

SELECT name

FROM sys.objects

WHERE object_id =

@@ProcID;

Connection

@@RowCount Number of rows returned by the last T-SQL

statement.

Connection

@@ServerName Name of the current server. Server

@@ServiceName SQL Server’s Windows service name. Server

@@SPID The current connection’s server-process identi-

fi er — the ID for the connection.

Connection

@@TranCount Number of active transactions for the current

connection.

Connection

@@Version SQL Server edition, version, and service pack. Server

c16.indd 405c16.indd 405 7/30/2012 5:38:09 PM7/30/2012 5:38:09 PM

http://www.it-ebooks.info