one of the documented procedures in this installation of the ACS
util_dbq { -null_is_null_p f } vars
What it does:
Given a list of variable names this routine creates variables named DBQvariable_name which can be used in sql insert and update statements.

If -null_is_null_p is t then we return the string "null" unquoted so that "update foo set var = $DBQvar where ..." will do what we want if we default var to "null".

Defined in: /web/philip/packages/acs-core/utilities-procs.tcl

Source code:

arg_parser_for_util_dbq $args

    foreach var $vars {
	upvar 1 $var val
        if [info exists val] {
            if { $null_is_null_p == "t" 
                 && $val == {null} } {
                uplevel [list set DBQ$var {null}]
            } else {
                uplevel [list set DBQ$var "'[DoubleApos [string trim $val]]'"]