"one-step" approach - sorted items

General
1

Hello,
Let’s say I have a table of a Workplace, which holds a List of Employee. I use the “one-step” approach to fetch them. Now, If I have a particular Workplace, and I want to retrieve a sorted list (by “firstname”, for example) of it’s Employees, What is the best way doing so?

Android - Java

Thank you.

2

Your QueryOptions has a property called ‘sortBy’ which can be used to sort the results https://backendless.com/documentation/data/android/data_search_and_query.htm

eg options.addSortBy(“firstname desc”)

3

Right, but for applying the addSortBy I need to query on the Employee class. it will return ALL the Employees in the table, not just the once related to a particular Workplace.

4

You can then add the WhereClause to filter the employees.

dataQuery.setWhereClause(“workplace.id = 1”) or something similair

5

Well, I can, but this is a bit messy. if I have a huge inventory of Employees (10^6), it would be very ineffective going through all of them, just to sort a few Employees of a particular Workplace. After all, this is why I store a list of them in the Workplace table the first place, to keep it effective.

I ask if there might be a better way of doing it.

Thank you for the replay.

6

If you have a lot of data, try to use such workaround.
Firstly - add index for column “name” in your Employe table.
Secondary - do not create relations to Workplace (to avoid joins), just use column “WorkplaceId” and add index for this column too.

Then use dataQuery.setWhereClause() and addSortBy() as usuall.

7

What about the option of adding a Workspace field into the Employee class that will simply point to it’s Workspace?

8

Sorting by relation field is not supported. You can sort only by primitive type columns.