Introduction to common global variables in SQL Server

InSQL ServerMedium,Global VariablesIs a special type of variable, the server will maintain the value of these variables. Global variables start with @ and do not need to be declared. They are system-defined functions. The following table lists some common global variables in SQL Server.

Global variable name	Description
@ Connections	Returns the number of connections that SQL Server has attempted since its last startup.
@ Cpu_busy	Returns the time that SQL server has been started since the last time.
@ Cursor_rows	Returns the number of currently limited rows in the previous cursor opened on the connection, Determine the number of rows that the cursor matches when it is called.
@ Datefirst	Returns the current set datefirst value for the session. Set datefirst indicates the specified The first day of each week.
@ Dbts	Returns the value of the current timestamp Data Type of the current database, The timestamp value must be unique in the database.
@ Error	Returns the error code of the last executed Transact-SQL statement, If the execution of the previous Transact-SQL statement is correct, 0 is returned.
@ Fetch_status	Returns the last cursor fetch sent for any cursor currently opened. Statement status.
@ Identity	Returns the id value inserted last time.
@ Idle	Returns the idle time of SQL Server since it was last started. The result is the CPU time. Incremental or "clock cycle" indicates the accumulation of all CPUs.
@ Io_busy	Returns the result of Microsoft SQL Server The time when the input and output operations are performed. The result is the CPU time increment. (Clock cycle), and is the cumulative value of all CPUs
@ Langid	Returns the local language identifier (ID) of the currently used language ).
@ Language	Returns the name of the current language.
@ Lock_timeout:	Returns the current lock timeout value of the current session in milliseconds ).
@ Max_connections	Returns the maximum number of concurrent user connections allowed by the SQL server instance. The returned value is not necessarily the currently configured value.
@ Max_precision	Returns the decimal and numeric data types according to the current settings on the server. The precision level used.
@ Nestlevel	Returns the nesting level of the current Stored Procedure executed on the local server (Initial Value: 0 ).
@ Options	Returns information about the current set option.
@ Pack_received	Returns the number of input data packets read from the Network since SQL Server was last started.
@ Pack_sent	Returns the number of output data packets written to the network after SQL Server is last started.
@ Packet_errors	Returns the network that has occurred on the SQL server connection since SQL Server was last started. Number of packet errors.
@ Procid	Returns the object identifier (ID) of the current Transact-SQL module ). Transact-SQL A module can be a stored procedure, user-defined function, or trigger.
@ Remserver	Return the name displayed in the logon record of the Remote SQL Server database server.
@ Rowcount	Returns the number of rows affected by the previous statement.
@ Servername	Returns the name of the local server that runs SQL Server.
@ Servicename	Returns the name of the registry that is running under SQL Server. If the current instance is For the default instance, @ servicename returns MSSQLServer.
@ Spid	Returns the session ID of the current user process.
@ Textsize	Returns the current value of the textsize option in the Set statement.
@ Timeticks	Returns the number of microseconds in each clock cycle.
@ Total_errors	Returns the number of disk write errors that SQL Server has encountered since its last startup.
@ Total_read	Returns the number of times that SQL Server reads a disk (not a high-speed cache read) since it was last started.
@ Total_write	Returns the number of disk writes performed by SQL Server since it was last started.
@ Trancount	Returns the number of active transactions for the current connection.
@@ version	returns the version, processor architecture, and generation date of the current SQL Server Installation. and operations system.