Loopback: Where filter not working in hasManyThrough relation in Loopback 3

[dromaludaire]

Context

I recently migrated an application from Loopback 2 to Loopback 3. After that process, queries involving a where filter on a hasManyThrough relation does not work anymore: they always return an empty array.

My application uses a mssql datasource, but I reproduced this behaviour on a minimal project using the memory datasource.

Description/Steps to reproduce

Create a new Loopback 3 application using loopback-cli. Then, reproduce the models of the official documentation for hasManyThrough relations :

• add 3 models (Physician, Patient, Appointment)
• add hasManyThrough relations between Physician and Patient
• add belongsTo relations between Appointment and Physician/Patient

With a simple test set, I get following results:

loopback > phy = Physician.findById(2)
{ name: 'Dr. Strangelove', id: 2 }
loopback > phy.patients({})
[ { name: 'Mickey', id: 2 }, { name: 'Minnie', id: 3 } ]
loopback > phy.patients({where: {name: 'Minnie'}})
[]

Although there is a patient related to the physician that matches the where filter, the result of the last query is empty. Note that I used loopback-console to get this output, but the API explorer gives the same results.

Expected result

When reproducing the above steps in a freshly loopback-cli-scaffolded Loopback 2 project, I get the following results :

loopback > phy = Physician.findById(2)
{ name: 'Dr. Strangelove', id: 2 }
loopback > phy.patients({})
[ { name: 'Mickey', id: 2 }, { name: 'Minnie', id: 3 } ]
loopback > phy.patients({where: {name: 'Minnie'}})
[ { name: 'Minnie', id: 3 } ]

This time, the last query anwers with a list containing the one patient related to the physician that matches the where filter, as expected.

Additional information

node -e 'console.log(process.platform, process.arch, process.versions.node)'

linux x64 6.11.0

yarn list --depth=0 | grep loopback

├─ [email protected]
├─ [email protected]
├─ [email protected]
├─ [email protected]
├─ [email protected]
├─ [email protected]
├─ [email protected]
├─ [email protected]
├─ [email protected]
├─ [email protected]
├─ [email protected]

lb --version

2.6.0 ([email protected] [email protected])

yarn --version

0.27.5

[dromaludaire]

Closing, since it should have been reported in strongloop/loopback-datasource-juggler.

In fact, an issue was reported, and a fixed is proposed, by @f0rmiga, see
strongloop/loopback-datasource-juggler#1406

[jannyHou]

hi @dromaludaire I am reviewing PR https://github.com/strongloop/loopback-datasource-juggler/pull/1406, and traced your issue here.

The PR is linked to a closed issue, while we usually open a new issue to describe the reproduce steps, track discussion and fix, the comments under PR should only be related to the code review.

Would you mind if I reopen this issue and continue the discussion here?

[f0rmiga]

Thank you for reproducing it @dromaludaire.

If you need anything else from me, please feel free to ask @jannyHou.

[dromaludaire]

hi @jannyHou ,

There are ofc no problem if you reopen this issue. (sorry for the delay, i was on vacation)

[adelriosantiago]

I am having the same issue, is there a solution or workaround to this?

[dromaludaire]

@adelriosantiago This regression was introduced in loopback-datasource-juggler 3.7.0. Therefore, you have two workarounds:

1. edit your package.json so as to use loopback-datasource-juggler=3.6.1 (latest working version)
2. apply the fix proposed by @f0rmiga in strongloop/loopback-datasource-juggler#1406

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[dromaludaire]

Looks like this will be closed when PR strongloop/loopback-datasource-juggler#1522 lands.

[jannyHou]

@dromaludaire Thanks for reminding. Closing it.

[jonathan-casarrubias]

@jannyHou I'm already in version 3.13.0 and I'm still unable to query related models when using hasManyThrough

a very simple query won't work

json { "where": {"email":"[email protected]"} }

We have had this issue for some time now, I was expecting strongloop/loopback-datasource-juggler#1522 fixed it but the problem remains.

This is a pretty basic query not working, are you guys having the same issue?

[dromaludaire]

@jonathan-casarrubias https://github.com/strongloop/loopback-datasource-juggler/pull/1522 indeed fixes this issue, but it was committed on Nov, 14, ie. after 3.13.0 was released. You can either wait for a new version of datasource-juggler to be released, or use the master branch.

[mikeevstropov]

Im using

• [email protected]
• [email protected]

roleMapping model has following relations

"role": {
  "type": "belongsTo",
  "model": "role",
  "foreignKey": "roleId"
},
"user": {
  "type": "belongsTo",
  "model": "user",
  "foreignKey": "principalId"
}

user model has

"roles": {
  "type": "hasMany",
  "model": "role",
  "foreignKey": "principalId",
  "through": "roleMapping",
  "keyThrough": "roleId"
},

and role has

"users": {
  "type": "hasMany",
  "model": "user",
  "foreignKey": "roleId",
  "through": "roleMapping",
  "keyThrough": "principalId"
},

When im trying to get related users from role like

role.users.find(filter);

the filter will apply to roleMapping instead of user collection.
How to fix it?