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PagedResultList .size() and .getTotalCount() return different values in grails gorm

I have the following code 

PagedResultList res = myService.getPage(paginateParams, ...)
println res.size() // returns 2
println res.getTotalCount() // returns 1

getPage looks like:

def criteria = MyDomain.createCriteria()
criteria.list(max: paginateParams.max, offset: paginateParams.offset) { // max is 10, offset is 0, sortBy is updatedAt and sortOrder is desc
    eq('org', org)
    order(paginateParams.sortBy, paginateParams.sortOrder)
}

why do the two method return different values? The documentation doesn't explain the difference, but does mention that getTotalCount is for number of records

currently on grails 2.4.5

edits:

println on res prints out:

res: [
com.<hidden>.MyDomain: 41679f98-a7c5-4193-bba8-601725007c1a, 
com.<hidden>.MyDomain: 41679f98-a7c5-4193-bba8-601725007c1a]

Yes, res has a SINGLE object twice - that's the bug I'm trying to fix. How do I know that? I have an primary key on MyDomain's ID, and when I inspect the database, it's also showing one record for this particular org (see my criteria)

edit 2: I found this comment (http://docs.grails.org/2.4.5/ref/Domain%20Classes/createCriteria.html)

listDistinct If subqueries or associations are used, one may end up with the same row multiple times in the result set. In Hibernate one would do a "CriteriaSpecification.DISTINCT_ROOT_ENTITY". In Grails one can do it by just using this method.

Which, if I understand correctly, is their way of saying "list" method doesn't work in this scenario, use listDistinct instead but then they go on to warn:

The listDistinct() method does not work well with the pagination options maxResult and firstResult. If you need distinct results with pagination, we currently recommend that you use HQL. You can find out more information from this blog post.

However, the blog post is a dead link.

Related: GORM createCriteria and list do not return the same results : what can I do?

Solution

  • After viewing related issues (GORM createCriteria and list do not return the same results : what can I do?) I determined that there were several approaches:

    1. Use grails projection groupBy('id') - doesn't work b/c i need the entire object

    2. USe HSQL - Domain.executeQuery - actually this didn't work for my scenario very well because this returns a list, whereas criteria.list returns a PagedResultList from which I previously got totalCount. This solution had me learning HSQL and also made me break up my existing logic into two components - one that returned PagedResultList and one that didn't

    3. Simply keep a set of IDs as I process my PagedResultList and make sure that I didn't have any duplicates.

    I ended up going with option 3 because it was quick, didn't require me to learn a new language (HSQL) and I felt that I could easily write the code to do it and I'm not limited by the CPU to do such a unique ID check.