Delete single array object in mongodb uing $unset

Question

https://mongoplayground.net/p/Yv6vkGyrUS-

https://mongoplayground.net/p/vm314GoexjE

[
 {
   "_id": ObjectId("4b253b067525f35f94b60a31"),
  "age": 30,
  "favorite book": [
  "Cat's Cradle",
  "Foundation Trilogy",
  "Ender's Game"
   ],
"location": "Wisconsin",
"name": "joe",
"sex": "male"
}
]

output delete any element with based on condition

"favorite book": [
  "Cat's Cradle",
  "Foundation Trilogy"
   ]

Look at https://stackoverflow.com/questions/13423873/deleting-a-single-object-from-an-array-of-objects-in-mongodb/13424041 — script0, Dec 16 '21 at 06:32
but i want del only array of obj a=[1,2,3] del a[1] now a=[1,3]... favbook=[1,2,3] del favbook[0] , favbook=[2,3] etc.. — suresh, Dec 16 '21 at 06:40

score 1 · Accepted Answer · answered Dec 16 '21 at 06:40

1

You can use $pull operator

db.collection.update({
    { _id : id },
    { $pull: { "favorite book": "Ender's Game" } }
});

If you want to remove two or more elements from the array "list", you can do that with $pull operator, as well:

db.collection.update({
    { _id : id },
    { $pull: { "favorite book" : { $in : [ "Foundation Trilogy", "Ender's Game"] } } }
});

Please check How do I remove a string from an array in a mongodb document?

answered Dec 16 '21 at 06:40

script0

387
2
12

its possible with unset ? – suresh Dec 16 '21 at 06:48
Yes. I think. But You will use the index of the element. But, it doesn’t remove the array element. Instead, it sets it to null. Check out https://www.mongodbtutorial.org/mongodb-crud/mongodb-remove-field-unset/ – script0 Dec 16 '21 at 07:09

Delete single array object in mongodb uing $unset

1 Answers1