Discriminator and dynamic table selection

Question

Is there a way (in DSP 3.0) to use a discriminator to dynamically determine a related table to join in a select or update? On the java client I have a base class with extended class that I would like to model in related tables.
Thanks,
Jeff
Edited by jhoffmanme at 02/08/2008 4:09 AM

Answer 1

Ok - so you want something like
<CASE>
<BASE_CASE>
<BASE_CASE>
<LAB_CASE>
</LAB_CASE>
<CASE>
<CASE>
<BASE_CASE>
<BASE_CASE>
<CS_CASE>
</CS_CASE>
<CASE>
So you will need to define a CASE schema element that contains a BASE_CASE, and optionally a LAB_CASE, CS_CASE etc. element.
your queries will look like :
function getLABCases()
for $base_case in BASE_CASES()
return
<CASE>
{$base_case}
{for $lab_case in LAB_CASES()
            where $lab_case/ID eq $case/ID
            return
              $lab_case
</CASE>
function getCSCases()
for $base_case in BASE_CASES()
return
<CASE>
{$base_case}
{for $cs_case in CS_CASES()
            where $cs_case/ID eq $case/ID
            return
              $cs_case
</CASE>
getAllCases()
( getLABCases(),
getCSCases() )
Use the nested for's as I have shown above rather than...
for $base_case in BASE_CASES()
for $lab-case in LAB_CASES()
where $lab_case/ID eq $base_case/ID
as the second way forces LAB_CASE table to be read even when it is not required in the output.
For updates, you will need visit the update template documentation to see how you tell DSP that a CASE with a LAB_CASE came from the LAB_CASES table.