Global Variables

Global variables are system-supplied variables that provide system-supplied values.

SAP Sybase IQ sets the values of global variables. For example, the global variable @@version has a value that is the current version number of the database server.

Global variables are distinguished from local and connection-level variables by two @ signs preceding their names. For example, @@error is a global variable. Users cannot create global variables, and cannot update the value of global variables directly.

Some global variables, such as @@spid, hold connection-specific information and therefore have connection-specific values. Other variables, such as @@connections, have values that are common to all connections.

Global Variable and Special Constants

The special constants such as CURRENT DATE, CURRENT TIME, USER, SQLSTATE, and so on are similar to global variables.

The following statement retrieves the value of the version global variable:

SELECT @@version

In procedures, global variables can be selected into a variable list. The following procedure returns the server version number in the ver parameter.

CREATE PROCEDURE VersionProc ( OUT ver
                 VARCHAR ( 100) )
BEGIN
    SELECT @@version
    INTO ver;
END

In Embedded SQL, global variables can be selected into a host variable list.

List of Global Variables

This table lists the global variables available in SAP Sybase IQ.

Variable name

Meaning

@@error

Commonly used to check the error status (succeeded or failed) of the most recently executed statement. Contains 0 if the previous transaction succeeded; otherwise, contains the last error number generated by the system. A statement such as if @@error != 0 return causes an exit if an error occurs. Every SQL statement resets @@error, so the status check must immediately follow the statement whose success is in question.

@@fetch_status

Contains status information resulting from the last fetch statement. @@fetch_status may contain the following values

  • 0 The fetch statement completed successfully.

  • -1 The fetch statement resulted in an error.

  • -2 There is no more data in the result set.

This feature is the same as @@sqlstatus, except that it returns different values. It is for Microsoft SQL Server compatibility.

@@identity

The last value inserted into an Identity/Autoincrement column by an insert, load or update statement. @@identity is reset each time a row is inserted into a table. If a statement inserts multiple rows, @@identity reflects the Identity/Autoincrement value for the last row inserted. If the affected table does not contain an Identity/Autoincrement column, @@identity is set to 0. The value of @@identity is not affected by the failure of an insert, load, or update statement, or the rollback of the transaction that contained the failed statement. @@identity retains the last value inserted into an Identity/Autoincrement column, even if the statement that inserted that value fails to commit.

@@isolation

Current isolation level. @@isolation takes the value of the active level.

@@procid

Stored procedure ID of the currently executing procedure.

@@rowcount

Number of rows affected by the last statement. The value of @@rowcount should be checked immediately after the statement. Inserts, updates, and deletes set @@rowcount to the number of rows affected. With cursors, @@rowcount represents the cumulative number of rows returned from the cursor result set to the client, up to the last fetch request. The @@rowcount is not reset to zero by any statement which does not affect rows, such as an IF statement.

@@servername

Name of the current database server.

@@sqlstatus

Contains status information resulting from the last FETCH statement.

@@version

Version number of the current version of SAP Sybase IQ.
Parent topic: Variables