Developers Knowledge Needed.. What / Why would someone use t

Steve

I'm going through web service code and the previous developer uses (STRSUBSTNO('@%1', in every setfilter statement such as...

Contact.SETFILTER(Name, STRSUBSTNO('@%1', Name));
Contact.SETFILTER(City, STRSUBSTNO('@%1', City));

rather than

Contact.SETFILTER(Name, '%1' , Name);
Contact.SETFILTER(City, '%1' , City);


It maybe full well something I'm unaware of, but I'm looking for suggestions to why he may have used STRSUBSNO and @ in every setfilter in the navision system.


Any ideas? :-k

Luc_VanDyck

The @-sign is used to filter on values regardless of case (= case insensitive).

Marije_Brummel

The @ makes it case insensitive.

I'm always fighting this with setfilter too, simply because it is something you don't do each day (understatement).

Just checked a customer database where I use the same construction, so I guess it makes sense. Although there might be me more roads that lead to rome.

Steve

so wouldn't this do the same thing..

Contact.SETFILTER(Name, '@%1' , Name);
Contact.SETFILTER(City, '@%1' , City);


No need for STRSUBSNO ??

Marije_Brummel

That's what I said. I just remember that I poked around with this getting it to work, and my customers db has the same solution.

It might work, it might have been a workaround in a certain version. My customer comes from 3.60 and runs on 2009 now.

Have you tested both?

Luc_VanDyck

I think you need to write it like this to get it working:

Contact.SETFILTER(Name, '%1' , '@' + Name);
Contact.SETFILTER(City, '%1' , '@' + City);

vaprog

Luc's version is the correct one.
Contact.SETFILTER(Name, '%1' , '@' + Name);

In the following construct, any characters in Name that have a special meaning in filter construction are use in that special meaning, so, if Name = 'Procter & Gamble', the construct will filter for a Name that is 'procter' (case insensitive) AND 'Gamble' (case sensiteve)
Contact.SETFILTER(Name, STRSUBSTNO('@%1', Name));
it is equal to
Contact.SETFILTER(Name, '@'+Name));

In the following construct, the string %1, which looks like a placeholder, will not be treated as such, but as the actual value. The last Name parameter is simply ignored and the filter filters for a literal '%1' (case insensitive, if that made sense)
Contact.SETFILTER(Name, '@%1', Name);


This is how I remember what SETFILTER will do:

1. The String parameter (2nd parameter) is parsed as a filter expression into it's atomic parts (values and operators) where all the special symbols mentioned in the help topic Entering Criteria in Filters are treated as operators, except for @, *, ? which are treated as part of the value.
2. Any value found in the preceding step that consist only of a placeholder will be replaced by the corresponding Value parameter (3rd and on) if such a parameter is given. Any special character within the Value is treated literally, except for @, *, ?.

EDIT: I renounce the following statement. There seems to be no way to let the filter engine treat the characters @, *, ? literally.
So, to be absolutely save, you'd need to write

Contact.SETFILTER(Name, '@'''+Name+''''));

(End of renouncement)