Wildcard query?

[johnkwaters]

How can I find say all the patients with an identifier that starts with ORG-SM-* ?

[mbaltus]

You cannot, since identifiers usually use the token search parameter type, and "A token type is a parameter that provides a close to exact match search on a string of characters" and "For tokens, matches are literal (e.g. not based on subsumption or other code system features).". See http://hl7.org/fhir/search.html#token for those details.
Your best bet IMHO would be searching for the namespace those identifiers come from, and then maybe do some more client-side filtering on the results.

[johnkwaters]

Ah - so this _lastUpdated is diifference from _since? What's the difference? And what would a query look like that searched for any patient that had changed since a given date?

[mbaltus]

Yes, _lastUpdated is a standard search parameter for all FHIR resources, shown in the summary table on the search page: http://hl7.org/fhir/search.html. _since is not an actual search parameter, but a parameter that sometimes is defined in operations, and for example for the history interaction.

[mbaltus]

Confusing, I must admit. _lastUpdated always looks at the lastUpdated field within the resource's metadata, whereas _since could include other things to determine what would match - although that would usually also involve the lastUpdated field...

[johnkwaters]

Trying to construct a search for all patients updates since a point in time:

var results = fc.Search<Patient>(
    new string[] { "_lastUpdated=2022-5-15" });

Is there some better way to generate a query using DateTimeOffsets? Not sure how to format this and can't find any examples in the unit tests.

[johnkwaters]

And interestingly, no matter what data I add, no entries are returned in the bundle!

var results = fc.Search<Patient>(
    new[] { "_lastUpdated=2010-01-01" });

I see this being sent:

GET https://fhir-st-mpi-clinical-dev.apps.okd.healthconcourse.com/Patient?_lastUpdated=2010-01-01

Do I need to include something else in the search?