A user or client application can query a global variable to find and view the property and processing values that affect that client connection.
A global variable represents one of the following:
The current value of a set statement, or
Information about the processing state of a connection.
Global variables are preceded by two “@@” characters and are not case sensitive. To query a global variable, issue a SQL statement:
select @@variable_name
where variable_name is the name of the relevant global variable.
Other rules that apply:
All global variables can be queried regardless of the SQL transformation mode in effect for the connection.
The select statement must be the only one in a batch.
The statement can be terminated with a semicolon.
Here is a SQL statement to query a global variable for the Client Interaction property, SendWarningMessages:
select @@SendWarningMessages
For a list of the configuration properties that you can use SQL statements to query a global variable, see Appendix A, “Configuration Quick Reference Table.”
