Sets the internal variable name to value or, if more than one value is given, to the concatenation of all of them. If no second argument is given, the variable is set with no value. To unset a variable, use the \ unset command.

Valid variable names can contain characters, digits, and underscores. See the section Variables below for details. Variable names are case-sensitive.

Note: vsql treats several variables as special. They are documented in Variables.