Lets quickly learn about using $and operator in MongoDB.
Related Read:
$exists, $type, $regex operators: MongoDB
$or (Union) Operator: MongoDB
Documents in our collection
test database, names collection.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | > db.names.find().pretty()
{ "_id" : ObjectId("53be5d4604cc1cb0a7bfc3c0"), "name" : "Alia" }
{ "_id" : ObjectId("53be5d5204cc1cb0a7bfc3c1"), "name" : "Bebo" }
{ "_id" : ObjectId("53be5d5904cc1cb0a7bfc3c2"), "name" : "Chameli" }
{ "_id" : ObjectId("53be5d6104cc1cb0a7bfc3c3"), "name" : "Dev D" }
{ "_id" : ObjectId("53be5d6804cc1cb0a7bfc3c4"), "name" : "Emli" }
{ "_id" : ObjectId("53be5d8604cc1cb0a7bfc3c5"), "name" : "Farhan" }
{ "_id" : ObjectId("53be5d9204cc1cb0a7bfc3c6"), "name" : "Gangs" }
{ "_id" : ObjectId("53be5d9904cc1cb0a7bfc3c7"), "name" : "Hum" }
{ "_id" : ObjectId("53be5e3704cc1cb0a7bfc3c8"), "name" : 25 }
{
"_id" : ObjectId("53beaa0f6a8a31dc255d4589"),
"name" : "Satish",
"age" : 27
} |
$and operator: MongoDB
[youtube https://www.youtube.com/watch?v=Ur0Mmj7yEOI]
YouTube Link: https://www.youtube.com/watch?v=Ur0Mmj7yEOI [Watch the Video In Full Screen.]
1 2 3 | > db.names.find({$and: [{"name": {$regex: "e"}}, {"name": {$gt: "C"}}]});
{ "_id" : ObjectId("53be5d5904cc1cb0a7bfc3c2"), "name" : "Chameli" }
{ "_id" : ObjectId("53be5d6104cc1cb0a7bfc3c3"), "name" : "Dev D" } |
As you can see, $and works/outputs results only when all the conditions in the array is met. i.e., in above command, the name must have small letter “e” in it and must be lexicographically greater than capital letter “C”.