MongoBD Learning (3) insert and query data
Root@adela-vm:/opt/mongodb_simple# numactl-- interleave=all bin/mongod-f conf/mongod.conf
About to fork child process, waiting until server is ready for connections.
Forked process: 4904
Child process started successfully, parent exiting
Root@adela-vm:/opt/mongodb_simple#. / bin/mongo 127.0.0.1:12345
MongoDB shell version: 2.6.9
Connecting to: 127.0.0.1:12345/test
> show dbs / / shows several databases
Admin (empty)
Local 0.078GB
> use adela / / switch to adela database without prior definition
Switched to db adela
> show dbs / / adela database does not add content, so it is not realistic
Admin (empty)
Local 0.078GB
>
The tables in RDBMS correspond to the collection collections in mongoDB, and the inserts are in json format
Db. Collection name (table) .insert (json format)
Db.adela_collection.insert ({"x": 1})
Show all collections
> show collections
Adela_collection
System.indexes
Insert data
> db.adela_collection.insert ({ypur2})
WriteResult ({"nInserted": 1})
> db.adela_collection.find ()
{"_ id": ObjectId ("5514f09641daf13c28f7bdb7"), "x": 1}
{"_ id": ObjectId ("5514f12b41daf13c28f7bdb8"), "y": 2}
_ id is automatically assigned by the system and can be customized, but _ id cannot be repeated.
> db.adela_collection.insert ({aVera 1, recorder 1})
WriteResult ({"nInserted": 1})
> db.adela_collection.insert ({aVera 2, recorder 1})
WriteResult ({
"nInserted": 0
"writeError": {
"code": 11000
"errmsg": "insertDocument:: caused by:: 11000 E11000 duplicate key error index: adela.adela_collection.$_id_ dup key: {: 1.0}"
}
})
Query adela_collection full table
> db.adela_collection.find () / / No parameters are added
Query data with x = 1
> db.adela_collection.find ({XRV 1})
{"_ id": ObjectId ("5514f09641daf13c28f7bdb7"), "x": 1}
{"_ id": ObjectId ("5514f1d241daf13c28f7bdb9"), "x": 1}
Insert a batch of data in a loop
> for (iTun1teri db.adela_collection.find ()
{"_ id": ObjectId ("5514f09641daf13c28f7bdb7"), "x": 1}
{"_ id": ObjectId ("5514f12b41daf13c28f7bdb8"), "y": 2}
{"_ id": ObjectId ("5514f1d241daf13c28f7bdb9"), "x": 1}
{"_ id": 1, "a": 1}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe54"), "z": 1}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe55"), "z": 2}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe56"), "z": 3}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe57"), "z": 4}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe58"), "z": 5}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe59"), "z": 6}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe5a"), "z": 7}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe5b"), "z": 8}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe5c"), "z": 9}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe5d"), "z": 10}
Count count
> db.adela_collection.find () .count ()
fourteen
How many pieces of data did skip skip?
Limit limits how many pieces of data to return
Sort uses sorting
> db.adela_collection.find ()
{"_ id": ObjectId ("5514f09641daf13c28f7bdb7"), "x": 1}
{"_ id": ObjectId ("5514f12b41daf13c28f7bdb8"), "y": 2}
{"_ id": ObjectId ("5514f1d241daf13c28f7bdb9"), "x": 1}
{"_ id": 1, "a": 1}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe54"), "z": 1}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe55"), "z": 2}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe56"), "z": 3}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe57"), "z": 4}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe58"), "z": 5}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe59"), "z": 6}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe5a"), "z": 7}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe5b"), "z": 8}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe5c"), "z": 9}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe5d"), "z": 10}
> db.adela_collection.find () .skip (4)
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe54"), "z": 1}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe55"), "z": 2}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe56"), "z": 3}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe57"), "z": 4}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe58"), "z": 5}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe59"), "z": 6}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe5a"), "z": 7}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe5b"), "z": 8}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe5c"), "z": 9}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe5d"), "z": 10}
> db.adela_collection.find () .skip (4) .limit (5)
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe54"), "z": 1}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe55"), "z": 2}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe56"), "z": 3}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe57"), "z": 4}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe58"), "z": 5}
> db.adela_collection.find () .skip (4) .limit (5) .sort ({zan1})
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe54"), "z": 1}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe55"), "z": 2}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe56"), "z": 3}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe57"), "z": 4}
{"_ id": ObjectId ("5514f5eca1b17c0bb936fe58"), "z": 5}
