Clarification: Multiple datasources in a report

[darth_fader]

You have a parent report with multiple subreports, A, B, C.  The parent report and A, B use the same datasource, C needs to use a different one.  

Simply pass the connection needed by C as a parameter to the parent report, then pass that parameter to the subreport as the connection expression, as follows.

in java, put the connection in a the jasperParameters map: 

            jasperParameters.put("oddBallConnection", connection);

 

in jrxml, add the following to the parent report:

        <import value="java.sql.Connection"/>

        <parameter name="oddBallConnection" class="java.sql.Connection"/>

 

add the following to the subreport reference <subreport> as follows:

 

<connectionExpression><![CDATA[$P{oddBallConnection}]]></connectionExpression>

 

You can use as many datasources/connections in jasper as you need.  I referred to the forums when I tried to solve this, and found various responses to the same question.  Hope this helps.

 

 

[kcd]

Nice thanks. Any chance you managed to get A and B to use the same datasource AND only query the database once? That is a problem I am facing.

[darth_fader]

Haven't had that situation come up yet; think a subreport is going to expect it's own query/fields etc. If A and B use the same datasource and query, then maybe subreport B isn't necessary. Maybe with some creative thinking you could get the data in the format you need in one report? Possibly use the summary band, or a table/frame/etc.?

[kcd]

Unless I am misunderstanding something (very possible!) the scenario isn't so unlikely if you use tables, which seem to act just like a subreport, and want a chart too (but not at the bottom)...

 

But yes my problem is quite different to just A and B subreports. I'm sure there is another method but anyway that is all covered in my post here.

 

http://jasperforge.org/plugins/espforum/view.php?group_id=102&forumid=103&topicid=92333

 

Thanks for replying, don't mean to hijack your post.