[DRIVERS-2728] Document that countDocuments() uses $match and may not support the same filters as find/count commands Created: 20/Sep/23 Updated: 21/Sep/23 |
|
| Status: | Backlog |
| Project: | Drivers |
| Component/s: | CRUD |
| Fix Version/s: | None |
| Type: | Spec Change | Priority: | Unknown |
| Reporter: | Jérôme Tamarelle | Assignee: | Unassigned |
| Resolution: | Unresolved | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
|
||||||||||||
| Driver Changes: | Needed | ||||||||||||
| Description |
SummaryUsing the $where operator in countDocument filter is not supported. As specified and implemented in drivers, the countDocuments operation uses an aggregation pipeline and copies the value of the filter argument into a $match stage. If the filter contains a $where operator, a server error is returned.
This is an issue because the signature of find(filter, options) and countDocuments(filter, options) are the same. So users expect to be able to use the same filter for both methods. Related discussion: https://github.com/mongodb/laravel-mongodb/discussions/2625 MotivationWho is the affected end user?Application developers How does this affect the end user?Yes, blocked. How likely is it that this problem or use case will occur?Everytime a developer tries to countDocuments on a find that they wrote using $where operator. If the problem does occur, what are the consequences and how severe are they?The command doesn't work. Developers must write their own aggregation pipeline or find a way to not use $where in the filter. Is this issue urgent?No Is this ticket required by a downstream team?No Is this ticket only for tests?No Acceptance CriteriaProvide an helpful error message or update the generated aggregation pipeline so that $where can be used in countDocuments. |
| Comments |
| Comment by Jeremy Mikola [ 21/Sep/23 ] |
|
This issue is not unique to $where, as it is only one of several restrictions when using $match (compared to typical query filters supported by find. Proposed action for this issue would be to require drivers to document that countDocuments() uses an aggregation pipeline and reference the server docs for potential differences/restrictions between $match and filters supported by find. |