Pagination in spring-data

Question

I have a requirement while querying a database using pagination. While pagination, I will give page size and page index to the query like shown below,

select distinct tp.* from kat_task_property tp inner join kat_task_to_workstream ttw on ttw.ttw_frn_task_id = tp.tp_frn_task_id and ttw.ttw_frn_workstream_id= :workStreamId and ttw.ttw_ended_by is null and tp.tp_ended_by is null and tp.tp_is_active=true and ttw.ttw_is_active=true left join kat_user_to_task_order kto on ttw.ttw_id = kto.uto_frn_task_to_workstream_id and kto.uto_frn_user_id = :userId order by tp.tp_completed_at ,kto.uto_order limit :index, :size

The sample result will be,

tp_id      tp_completed_at
 1          2017-02-27 06:47:52
 2          null
 3          null
 4           2017-03-14 12:59:24
 5          null
 6          null
 7          null

My requirement is when index is 0 in the query, I should get all the data where tp_completed_at is null irrespective of the value size has in the query. I mean, pagination should not be applied when index is zero and I should get all the entries with tp_completed_at is null. And, when index has value other than 0 pagination should apply. Please Help

Answer 1

you can use Pageable to do that. PageRequest(page, size)

Pageable page = new PageRequest(0, 10);

for example :

Page<Incident> findByProblemId(Long problemId, Pageable page);

In your case , countQuery = ".... count(distinct tp.*) ... without limit"

@Query(value = "your existing Query without limit ", countQuery = "countQuery", nativeQuery = true)
getData(@Param("workStreamId") String workStreamId, @Param("userId") String userId, Pageable page);

Answer 2

You can achieve this by executing different queries based on the index value.

Edit: Try this hack, Works if your result set is less than Integer.MAX_VALUE

@Query("select distinct tp.* from kat_task_property tp inner join kat_task_to_workstream ttw on ttw.ttw_frn_task_id = tp.tp_frn_task_id and ttw.ttw_frn_workstream_id= :workStreamId and ttw.ttw_ended_by is null and tp.tp_ended_by is null and tp.tp_is_active=true and ttw.ttw_is_active=true left join kat_user_to_task_order kto on ttw.ttw_id = kto.uto_frn_task_to_workstream_id and kto.uto_frn_user_id = :userId and order by tp.tp_completed_at, kto.uto_order")
Page<T> findTp(Pageable pageable);

PagingAndSortingRepository<YourObject, Long> repository = // … get access to a bean
if(index == 0)
    Page<YourObject> yourObject= repository.findTp(new PageRequest(index, Integer.MAX_VALUE));
else
    Page<YourObject> yourObject= repository.findTp(new PageRequest(index, size));