$in requires an array as a second argument, found: missing

by

First option –> Use aggregation

Because your some of the documents in your collection may or may not contain permissions field or is type not equal to array that’s why you are getting this error.

You can find the $type of the field and if it is not an array or not exists in your document than you can add it as an array with $addFields and $cond aggregation

db.collection.aggregate([
  { "$addFields": {
    "permissions": {
      "$cond": {
        "if": {
          "$ne": [ { "$type": "$permissions" }, "array" ]
        },
        "then": [],
        "else": "$permissions"
      }
    }
  }},
  { "$project": {
    "filteredChildren": {
      "$filter": {
        "input": "$moduleChildren",
        "as": "moduleChild",
        "cond": {
          "$in": [ "$$moduleChild._id", "$permissions" ]
        }
      }
    }
  }}
])

Second option –>

Go to your mongo shell or robomongo on any GUI you are using and run
this command 

db.collection.update(
  { "permissions": { "$ne": { "$type": "array" } } },
  { "$set": { "permissions": [] } },
  { "multi": true }
)

More Related Contents:

  1. MongoDB: find and findOne with nested array filtering
  2. How to Update Multiple Array Elements in mongodb
  3. MongoDB – Query on the last element of an array?
  4. Querying MongoDB to match in the first item in an array
  5. Group result by 15 minutes time interval in MongoDb
  6. Moongoose aggregate $match does not match id’s
  7. Find in Double Nested Array MongoDB
  8. MongoDB: How do I update a single subelement in an array, referenced by the index within the array?
  9. Check if every element in array matches condition
  10. Get a count of total documents with MongoDB when using limit
  11. Include all existing fields and add new fields to document
  12. Matching ObjectId to String for $graphLookup
  13. mongodb count num of distinct values per field/key
  14. MongoDB aggregation comparison: group(), $group and MapReduce
  15. Mongodb aggregation lookup with conditions
  16. MongoDB group by array inner-elements
  17. Multiple Counts with single query in mongodb
  18. Get particular element from mongoDB array [duplicate]
  19. How to return array of string with mongodb aggregation
  20. MongoDB update multiple records of array [duplicate]
  21. How to return just the nested documents of an array from all documents
  22. Updating nested array inside array mongodb [duplicate]
  23. Get n-th element of an array in MongoDB
  24. How do I rename fields when performing search/projection in MongoDB?
  25. mongodb aggregation framework match by nested documents
  26. Removing the array element in mongoDB based on the position of element
  27. count array occurrences across all documents with mongo
  28. Mongodb, aggregate query with $lookup
  29. mongodb get _id as string in find query
  30. Return the last “true” value for each group

Leave a Comment