mongodb 存储结构:database > collection > document
mongo
show dbs
use saber2pr
db.createCollection("qwq")
show collections
db.qwq.insert({name: "saber"})
db.qwq.find({name: "saber"})
db.qwq.find()
db.qwq.remove({name: "saber"})
db.qwq.remove({})
db.qwq.drop()
use saber2pr
db.dropDatabase()