I am having similar problems but can't find any solution.
Here is my case.
report_group can have many report_types and many reports. No relation exists
for report_type and reports. Here is the result of a query to get a
report_group.
report_group_id report_id report_type_id
100 35 1
100 35 2
100 36 1
100 36 2
100 37 1
100 37 2
Now, desired result is:
ReportGroup with
3 Report {35, 36, 37} and 3 ReportType {1, 2}.
I have put groupBy="id" in all of the 3 resultMap (report_group, reports,
report_types), but I am getting a ReportGroup with
3 Report {35, 36, 37}
& 6 ReportType(1, 2, 1, 2, 1, 2) i.e. 6 ReportType object being repeated
with every Report.
How can I solve the problem? Any help is greatly appreciated.
Heinrich Götzger wrote:
>
> Hello,
>
> I'm wondering if iBATS help me for solving _two_ N plus 1 problems
> within one select:
>
> Let's assume a result as follows:
>
> main group_A group_b
> -------------------------------
> parent1, child_a1, null
> parent1, child_a2, null
> parent1, null, child_b1
> parent1, null, child_b2
> parent2, child_a4, null
> parent2, null, child_b3
> parent3, child_a5, null
> parent3, child_a6, null
> parent3, child_a7, null
> parent3, null, child_b4
>
> How would I get a list of main-beans with:
> - parent1: containing list child_a(a1, a2), list child_b(b1, b2)
> - parent2: containing list child_a(a4), list child_b(b3)
> - parent3: containing list child_a(a5, a6, a7), list child_b(b4)
>
> Group a and group b are not related to each other. They are only related
> to parent
>
> A more convenient solution could be the usage of collection types in the
> result set. This would lead to a collection of group a and one of group
> b. The resulting main-beans would be the same.
> Is there some support in iBATIS for collection types?
>
>
> Thanks for some thoughts and some help.
>
> Cheers
>
> Heinrich
>
>
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