Find document with array that contains a specific value

Question

If I have this schema     person         name   String      favoriteFoods   Array         where the favoriteFoods array is populated with strings  How can I find all persons that have  sushi  as their favorite food using mongoose   I was hoping for something along the lines of   PersonModel find   favoriteFoods      contains    sushi     function                 I know that there is no  contains in mongodb  just explaining what I was expecting to find before knowing the solution

User · Answer

There is no  contains operator in mongodb   You can use the answer from JohnnyHK as that works  The closest analogy to contains that mongo has is  in  using this your query would look like   PersonModel find   favouriteFoods      in      sushi

User · Answer

For Loopback3 all the examples given did not work for me  or as fast as using REST API anyway  But it helped me to figure out the exact answer I needed     where    arrayAttribute     all    String

User · Answer

If you d want to use something like a  contains  operator through javascript  you can always use a Regular expression for that     eg  Say you want to retrieve a customer having  Bartolomew  as name  async function getBartolomew         const custStartWith Bart   await Customers find  name    Bart         Starts with Bart     const custEndWith lomew   await Customers find  name   lomew          Ends with lomew     const custContains rtol   await Customers find  name     rtol           Contains rtol      console log custStartWith Bart       console log custEndWith lomew       console log custContains rtol

User · Answer

As favouriteFoods is a simple array of strings  you can just query that field directly  PersonModel find   favouriteFoods   quot sushi quot              favouriteFoods contains  quot sushi quot   But I d also recommend making the string array explicit in your schema  person         name   String      favouriteFoods    String     The relevant documentation can be found here   https   docs mongodb com manual tutorial query-arrays

User · Answer

Incase of lookup food array is array   match stage  favoriteFoods        elemMatch      in   lookup food array     Incase of lookup food array is string   match stage  favoriteFoods        elemMatch   lookup food string

User · Answer

I know this topic is old  but for future people who could wonder the same question  another incredibly inefficient solution could be to do   PersonModel find   where    this favouriteFoods indexOf  sushi      -1       This avoids all optimisations by MongoDB so do not use in production code

User · Answer

I feel like  all would be more appropriate in this situation  If you are looking for person that is into sushi you do    PersonModel find   favoriteFood      all     sushi              As you might want to filter more your search  like so    PersonModel find   favoriteFood      all     sushi    bananas               in is like OR and  all like AND  Check this   https   docs mongodb com manual reference operator query all

User · Answer

In case you need to find documents which contain NULL elements inside an array of sub-documents  I ve found this query which works pretty well   db collection find   keyWithArray    elemMatch    in   null     exists  true       This query is taken from this post  MongoDb query array with null values  It was a great find and it works much better than my own initial and wrong version  which turned out to work fine only for arrays with one element     find        MyArrayOfSubDocuments      not     size  0           MyArrayOfSubDocuments  id      exists  false

User · Answer

In case that the array contains objects for example if favouriteFoods is an array of objects of the following       name   Sushi     type   Japanese      you can use the following query   PersonModel find   favouriteFoods name    Sushi

User · Answer

Though agree with find   is most effective in your usecase  Still there is  match of aggregation framework  to ease the query of a big number of entries and generate a low number of results that hold value to you especially for grouping and creating new files      PersonModel aggregate                                     match                            and       favouriteFoods       exists  true   in     sushi                                                    project      id   0   name    1

[mongodb] Find document with array that contains a specific value

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