Using ORDER BY ASC on a string with number

Support
1

Hi guys,

Say I have the following results that comes from two variables in my SPARQL query:

?wall ?ID
:wall1 “AB21”
:wall2 “AB14”
:wall3 “AB2”
:wall4 “AB3”

When I use ORDER BY ASC(?ID) I get the following:

?wall ?ID
:wall1 “AB14”
:wall2 “AB2”
:wall3 “AB21”
:wall4 “AB3”

Since I think it only looks for the next item in the string (i.e. 1, 2, 21, 3), but is there a way to treat it as an integer or make it look at the full number?

2

You’ll probably need to take the integer suffix of ?ID bindings to a separate variable (using xsd:integer for casting), then order by that one. Strings are sorted lexicographically.

Cheers,
Pavel

3

Is there any way to define a custom sort order for a user defined datatype? Plugin perhaps? Just curious.

4

Not directly, but one can have a user-defined function which maps values of custom datatypes to integers… That’d be another way to solve the topic starter’s problem but perhaps an overkill here.

Cheers,
Pavel