Subject Re: canOpen firing twice for DMD's query object + unexpected =/== From Mervyn Bick <invalid@invalid.invalid> Date Fri, 18 Sep 2020 10:34:50 +0200 Newsgroups dbase.getting-started On 2020/09/17 03:07, Gaetano wrote: > In the following code, if I change the "==" operator to "=" in the DO > CASE block, the first DO CASE clause evaluates to true (i.e. the code > sees _app.varSQL as being an empty string) and cSQL doesn't get updated > as I expected it to in the second CASE clause. > > I believe that the clause should not evaluate to true because > _app.cVarSQL is set to "getMissDaysDetails" and doesn't have any > trailing/inbetween/leading spaces. Any idea why the single "=" is not > working in that context? > This is a known "gotcha". :-) With EXACT set OFF (the default and recommended setting) the = symbol is equivalent to "begins with". According to the help file entry for = all strings begin with an empty string so ""=_app.cVarSQL will always return true.  It recommends testing for  _app.cVarSQL="" The alternative is to use the == exactly equals symbol as you have done or case empty(_app.cVarSQL) Mervyn.