In QMF, a global variable keeps its value from the time it is set until you either reset it or end your QMF session. Use global variables to assign changing values to substitution variables in queries, procedures, and forms. You can also use global variables to change certain behavioral aspects of your QMF session, such as displaying confirmation panels in the Table Editor.
Each global variable has a name and a value. Creating, changing, and deleting global variables using commands discusses limitations for the lengths of names and values. Some variable names are reserved for use by QMF. These names begin with the letters DSQ.
Variable values used in queries cannot begin with dashes because the database misinterprets them. The command for viewing global variables is SHOW GLOBALS.
This command lists global variables and their values. From the global variable list, you can change or delete an existing global variable or add a new one.
You can also use the SET GLOBAL and RESET GLOBAL commands from the QMF command line to set and delete global variables without displaying the global variable list.
This chapter describes how to use the global variable list and the SET GLOBAL and RESET GLOBAL commands. For information and examples on other aspects of using variables in queries, forms, or procedures, see Making your query reusable with substitution variables, Making your query reusable with substitution variables, Using a global variable in a heading or footing, and Specifying values for variables using global variables.