Add, delete and modify operations in MongoDB
Addition, deletion, modification and search of MONGODB:
Note: the field "_ id" is the GUID added to us by default by the database to ensure the uniqueness of the data.
1. Add insert
1. Grammar: db. Collection .insert ({"key1": value1, "key2": value2,. "keyN": valueN})
> db.wqq.insert ({"name": "wqq", age:25,height:1.65,dep: "DEGREE"})
WriteResult ({"nInserted": 1})
# # insert a value that can specify _ id, as well as nesting between other values
For (iSuppli id: 119, "age": 41, "name": "aaa19"})
WriteResult ({"nMatched": 0, "nUpserted": 1, "nModified": 0, "_ id": 119})
2. Insert multiple entries:
Db.abc.insert ([{name: "wangwu", age:22,sex:1,class: "jsj"}, {name: "aaa", age:22,sex:1,class: "bdd"}])
2. Find find
1. Find all: db. Collection. Find ()
2. Conditional search: db. Collection. Find ({"key1": value1, "key2": value2,. "keyN": valueN})
3. Other statistics
Db.wqq.count () db.wqq.find () .count () / Statistics
Db.wqq.find (). Sort ({name:-1}) / / sort-1 is descending and 1 is ascending
Db.wqq.find (). Limit (4) / / how many
Db.wqq.find (). Limit (4). Pretty () / / formatted display
Db.wqq.find () .skip (4) .limit (10) / / Skip several values
Db.wqq.find (). Skip (4) .limit (10). Sort ({"_ id":-1}) / / take several values by sorting them
Db.wqq.find ({"age": {$all: [110]}})
Db.wqq.find ({"age": {$in: [110111112.]}}) / / returns the value that exists in the array
Db.wqq.find ({"age": {$nin: [110111112.]}}) / / returns the value that exists in the array
Db.wqq.find ({"age": {$exists:1}}) / / check whether a field exists
Db.wqq.find ({"age": {$mod: [10LJ 2]}}) / / returns the value equal to the remainder after the field is modeled.
Db.wqq.find ({$or: [{"age": 40}, {"name": "aaa19"}]}) / / View the records of specified conditions, similar to SQL's OR
Db.wqq.find ({$nor: [{"age": 40}, {"name": "aaa19"}]}) / / contrary to or
# # comparison operator
$gt: greater than $gte: greater than or equal to $lt: less than $lte: less than or equal to $ne: not equal to
Db.wqq.find ({"age": {$lt:100}})
# # logical Operation
And operation:
Db.wqq.find ({age:23,name: "aaa1"})
Or ($in) / not $nin
Db.wqq.find ({age: {$in: [11Jing 222pm 33444]}})
# # regular matching
Db.wqq.find ({name:/aaa/})
# # $where
/ / return the document containing the login_name field
Db.getCollection ('users') .find ({$where:function () {
Return!! this.login_name
})
# # and Operation
Db.wqq.find ({name: "wangwu", class: "jsj"})
# # combined query
Db.abc.find ({name: {$exists:1,$nin: ["Zhang San"]}}) / / field exists and is not called "Zhang San"
3. Update update ()
1. Update a field:
Db.wqq.update ({age:42}, {$set: {name: "sbt"}})
2. Add a field value to a document or if it does not exist
Db.wqq.update ({name: "aaa78"}, {$inc: {age:2}}, 0jin1)
3. Batch update. If there is an update in the field, if there is no additional field in the field.
Db.wqq.update ({name: "aaa"}, {$set: {age:2}}, false,true)
Db.wqq.update ({name: "Zhang San"}, {$set: {age:3}}, 0jin1)
4. A collection has only one key-value update
Db.wqq.update ({name: "Zhang San"}, {name: "Mo Wing Lun"})
4. Delete
1. Delete some documents
Db.wqq.remove ({"name": "abc"})
2. Delete the entire collection:
Db.wqq.drop ()
3. Delete which article
Db.wqq.remove ({name: "abc"}, 2)
4. Delete a field
Db.abc.update ({}, {$unset: {age:50}}, 0jue 1) / / Delete multiple fields, and delete the first field without adding 0J1.
5. The use of cursors
Var x=db.wqq.find ()
X.next ()
X.hasNext ()
While (x.hasNext () = = true) {x.next ()}
6. Add an array to the collection and pop up
Db.abc.update ({}, {$push: {arr:3}}) / / add a worthy array
Db.abc.update ({}, {$pushAll: {arr: [1, 2, 3, 4, 5, 6, 7, 8, 9]}) / / add multiple worthy arrays
Db.abc.update ({}, {$pop: {arr:1}}) / / the last value of the pop-up array, and-1 is the first value of the array
Db.abc.update ({name: "Zhang San"}, {$pull: {arr:4}}, 0jin1) / / deletes the specified value of the array
Db.abc.update ({}, {$addToSet: {arr:6}}, 0J1) / / add an array to the array, and do not repeat it if it exists.
Db.abc.update ({name: "Zhang San"}, {$addToSet: {$each: {$each: [1meme 2meme 3meme 4]}, 0meme 1) / / is used to run the modifier to manipulate data to the collection multiple times.
