Select app_name () as appname -- Name of the application in the current session.
Select @ error -- return the error code (integer) of the last executed Transact-SQL statement ).
Select @ identity -- return the last inserted id value.
Select user_name () -- returns the user database username.
Select @ connections -- returns the number of connections or attempts since the last SQL startup.
Select getdate () -- current time.
Select @ cpu_busy/100 -- returns the CPU time (in milliseconds) since the last SQL statement was started ).
Use tempdb select @ dbts as timestamp -- returns the current timestamp data type value for the current database. This timestamp value must be unique in the database.
Select @ idle as temp -- returns the idle time (in milliseconds) of the SQL statement since it was last started ).
Select @ io_busy as w -- returns the time (in milliseconds) that the SQL statement was used to perform input and output operations since the last time it was started ).
Select @ langid as w -- returns the local language identifier (ID) of the current language ).
Select @ language as w -- returns the current language name.
Select @ lock_timeout as w -- set the current lock timeout for the current session (unit: milliseconds ).
Select @ max_connections as w -- returns the maximum number of simultaneous user connections allowed on SQL. The number returned does not need to be the currently configured value.
Exec sp_configure -- display the global configuration settings of the current server.
Select @ max_precision as w -- return the precision level used by the decimal and numeric data types, that is, the currently set precision on this server. The default maximum precision is 38.
Select @ options as w -- returns information about the current set option.
Select @ pack_received as w -- returns the number of input data packets read from the network after SQL is started.
Select @ pack_sent as w -- return the number of output data packets written to the network by sq since the last start.
Select @ packet_errors as w -- returns the number of network packet errors that have occurred on the SQL connection since the SQL startup.
Select @ servername as w -- return the name of the running SQL Server.
Select @ servicename as w -- return the registry key name that is running under the SQL statement.
Select @ timeticks as w -- returns the number of microseconds at a scale of the SQL Server.
Select @ total_errors as w -- returns the number of disk read/write errors that the SQL Server encounters after it is started.
Select @ total_read as w -- returns the number of times the SQL Server reads the disk after it is started.
Select @ total_write as w -- return the number of times the SQL server writes data to the disk after it is started.
Select @ trancount as w -- returns the number of active transactions for the current connection.
Select @ version as w -- returns the date, version, and processor type of the SQL Server installation. # Database Technology
