Passed parameters and selection sets

[Ray Scheel]

I was trying to modify a selection (called from a php-built web form /
command line) that currently selects the desired unit to also be able to
select all a defined regional grouping based on the contents of a passed
parameter.  Line "a" works fine, field 5:unitcd(2,*), is correctly
compared to the contents of @pm.  Where I ran into trouble was when
trying to add logic to catch the codes for the larger groupings.

I would enter and save a selection set like this:
a      |  5  | unitcd ; unit code      eqf|   @pm|
b      |  @pm| Parameter               eq |   _North
|
c      |  @pm| Parameter               eq |   _South
|
Selector Sentence:
a or (b and north) or (c and south)

but when I came back to it, what showed up was this:
a      |  5  | unitcd ; unit code      eqf|   @pm|
b      |  @pm| Parameter               eq |   _|
c      |  @pm| Parameter               eq |   _|
Selector Sentence:
a or (b and north) or (c and south)

Note the stripping down of the "Value" column to one character.

I had identical results when using @pw- at pz and when trying "co" instead
of "eq". Behavior for passed parameters verified on linux versions of
both 5.0.11aR4 and 5.0.14R4.  The behavior did not carry over when
trying a few other system maintained fields, it apparently only impacts
passed parameters.

I'm going to work around this by selecting all records in the selection
set when I've got a leading "_" in the unitcd and will instead drop the
unwanted units in sort/selection processing (referring back the
selection set "north", "south", etc).

Has anyone else run into this?  Is there an unadvertised fix or setting
to change this behavior, or documentation that their use in selection
sets isn't supported or is (sometimes) limited to the first character?
Should I just give up on using passed parameters for much of anything in
selection processing since I keep tripping over significant bugs (e.g.
the incompatibility with index scan I discovered about a year ago)?
Surely I'm not the only person trying to use command line parameters in
selection sets, am I?  I'm getting tired of getting well into a project
and then having to stop to identify an issue or undocumented limitations
and then come up with a workaround to compensate.


Ray Scheel               ray.scheel at wsdtx.org
Windham School District     Computer Services
Programmer                       936-291-5206