Strict equality checks for simple arrays

[Fronix]

I have an issue where i have an array that i want to filter but the IN and = operators don't work as strict equality checks for simple arrays but rather as includes. Eg

• filter: "attribute IN [this, that]"
• filter: "attribute=this OR attribute=that"
• filter: "(attribute=this OR attribute=that) OR (attribute=this AND attribute=that)"

Will all include documents that may have a document with these values attribute: ["this", "that", "other"]

Example:
In this example i want to find all the documents that have E01 Psykiatri or E02 Barn- och ungdomspsykiatri or both but not anything else.

This filter: "filter": "specializations IN [\"E01 Psykiatri\", \"E02 Barn- och ungdomspsykiatri\"]" will return all documents including id: 4.

This is fine but sometimes you want to be exact and what I feel is missing is a strict version of IN and = operator for simple arrays.

Something like this: "filter": "specializations ONLY IN [\"E01 Psykiatri\", \"E02 Barn- och ungdomspsykiatri\"]" which will return documents that only has both values or one of them eg documents 1 2 and 3

Data:

[
{
  "id": 1,
  "name": "Testing",
  "specializations": ["E01 Psykiatri", "E02 Barn- och ungdomspsykiatri"]
},
{
  "id": 2,
  "name": "Testing2",
  "specializations": ["E01 Psykiatri"]
},
{
  "id": 3,
  "name": "Testing3",
  "specializations": ["E02 Barn- och ungdomspsykiatri"]
},
{
  "id": 4
  "name": "Testing4",
  "specializations": ["E04 Äldrepsykiatri","E01 Psykiatri"]
}
]

Current workaround

My current workaround for this is to filter the results and remove anything that doesn't exactly have what was filtered for, this works fine but when using packages like instant-meilisearch it adds a lot of overhead and I feel like this should be a standard feature.

Important note:
It's impossible to ensure that you get all the results if the filtered results are more than the maxpage results.

So if my filter returns 200 results and i show 100 results per page, there might be "workaround results" on page 2 that get missed. There is no way to find those without brute force, which negates the whole point of filtering.

---

This discussion might be slightly related: https://github.com/orgs/meilisearch/discussions/675

[macraig]

Hi @Fronix , thank you for taking the time to leave your feedback and explain your use case. This is indeed a limitation of how the engine filters currently work; I'm glad you found a workaround that works for you for the time being.

To share some extra context, we're currently concentrating our efforts on enhancing the quality of our service. This means we don't have the bandwidth to implement all the feature requests we get immediately. However, your feedback has been noted and will be considered as we continue to improve and evolve. I'll leave the discussion open for other users to upvote if they have the same need.

Once again, thank you for your feedback!

[Fronix]

Hi @macraig, I understand. Something that i did forget to mention in the workaround is that it's impossible to ensure that you get all the results if the filtered results are more than the maxpage results.

So if my filter returns 200 results and i show 100 results per page, there might be "workaround results" on page 2 that get missed. There is no way to find those without brute force, which negates the whole point of filtering.