Query for documents where array size is greater than 1

Question

I have a MongoDB collection with documents in the following format         id    ObjectId  4e8ae86d08101908e1000001       name      Name       zipcode      2223           id    ObjectId  4e8ae86d08101908e1000002       name      Another     Name       zipcode      2224       I can currently get documents that match a specific array size    db accommodations find   name      size   2       This correctly returns the documents with 2 elements in the name array  However  I can t do a  gt command to return all documents where the name field has an array size of greater than 2   db accommodations find   name      size     gt   1         How can I select all documents with a name array of a size greater than one  preferably without having to modify the current data structure

User · Answer

None of the above worked for me  This one did so I m sharing it   db collection find   arrayName     exists true    where  this arrayName length gt 1

User · Answer

I found this solution  to find items with an array field greater than certain length  db allusers aggregate       match  username   exists true         project    count     size   locations lat           match  count   gt 20         The first  match aggregate uses an argument thats true for all the documents   If blank  i would get    errmsg     exception  The argument to  size must be an Array  but was of type  EOO

User · Answer

You can MongoDB aggregation to do the task  db collection aggregate            addFields          arrayLength    size    array                        match          arrayLength    gt  1

User · Answer

You can use aggregate  too   db accommodations aggregate           project    id 1  name 1  zipcode 1                    size of name    size    name                                    match    size of name     gt  1            you add  size of name  to transit document and use it to filter the size of the name

User · Answer

I know its old question  but I am trying this with  gte and  size in find  I think to find   is faster   db getCollection  collectionName   find   name      gte       size   1

User · Answer

There s a more efficient way to do this in MongoDB 2 2  now that you can use numeric array indexes in query object keys      Find all docs that have at least two name array elements  db accommodations find   name 1     exists  true      You can support this query with an index that uses a partial filter expression  requires 3 2        index for at least two name array elements db accommodations createIndex        name 1   1        partialFilterExpression    name 1     exists  true

User · Answer

MongoDB 3 6 include  expr https   docs mongodb com manual reference operator query expr   You can use  expr in order to evaluate an expression inside a  match  or find      match                expr    gt     size    yourArrayField    0                  or find  collection find   expr    gte     size    yourArrayField    0

User · Answer

db inventory find    dim cm     elemMatch     gt  22   lt  30          you can use  gt and  lt in query

User · Answer

Try to do something like this   db getCollection  collectionName   find   ArrayName 1     exists  true      1 is number  if you want to fetch record greater than 50 then do ArrayName 50 Thanks

User · Answer

Update   For mongodb versions 2 2  more efficient way to do this described by  JohnnyHK in another answer     1 Using  where  db accommodations find     where   this name length  gt  1         But        Javascript executes more slowly than the native operators listed on   this page  but is very flexible  See the server-side processing page   for more information    2 Create extra field NamesArrayLength  update it with names array length and then use in queries   db accommodations find   NamesArrayLength     gt  1        It will be better solution  and will work much faster  you can create index on it

User · Answer

I believe this is the fastest query that answers your question  because it doesn t use an interpreted  where clause     nor         name    exists  false         name    size  0         name    size  1        It means  all documents except those without a name  either non existant or empty array  or with just one name    Test    gt  db test save      gt  db test save  name        gt  db test save  name    George      gt  db test save  name    George    Raymond      gt  db test save  name    George    Raymond    Richard      gt  db test save  name    George    Raymond    Richard    Martin      gt  db test find   nor    name    exists  false     name    size  0     name    size  1          id    ObjectId  511907e3fb13145a3d2e225b     name       George    Raymond          id    ObjectId  511907e3fb13145a3d2e225c     name       George    Raymond    Richard          id    ObjectId  511907e3fb13145a3d2e225d     name       George    Raymond    Richard    Martin       gt

User · Answer

Although the above answers all work  What you originally tried to do was the correct way  however you just have the syntax backwards  switch   size  and   gt      Correct   db collection find  items    gt    size  1       Incorrect   db collection find  items    size    gt  1

User · Answer

You can use  expr   3 6 mongo version operator   to use aggregation functions in regular query    Compare query operators vs aggregation comparison operators   db accommodations find   expr   gt    size   name    1

User · Answer

db accommodations find   name     exists  true    ne        not     size  1

[mongodb] Query for documents where array size is greater than 1

Examples related to mongodb

Examples related to mongodb-query