MongoDB Database Basics

MongoDB Database

View database: Show DBS;

Create/Switch database: Use F28 (F28 for database name)

To view a running database: DB;

Crud Additions and deletions (create retrive update delate)

Add: Insert

db.users.insert({username:"jack",password；123456})

Delete: Remove

Dropdatabase (); Delete the current database

Db.users.remove ({username: "aaaaaa"})//delete only this piece of data

Db.users.remove (); All the data from the users are deleted.

Change: Update

db.users.update({username:"bbbbbb",{$set:{password:222222}}})//只修改username为bbbbbb里的passworddb.users.update({username:"aaaaaa"},{password：111111})//这条数据将被password替换掉db.users.update({},{$set:{password:22222}},{multi:true});3.0新版本修改所有passworddb.users.update({},{$set:{password:22222}},false,true);3.0一下旧版本修改所有password

Poor: Find

db.users.find().pretty();//查看所有被整理后的数据（即被美化）db.users.find({username:"aaaaaa"})//精确匹配db.users.find({age:{$gt:20}});//匹配年龄大于20的db.users.find({age:{$gt:20，$lt:30}})//匹配年龄大于20的,且小于30的db.users.find({age:{$gt:20}，gender:"male"});//匹配年龄大于20的,且是男的db.users.find({$or:[age:{$gt:20},{gender:"male"}]});//匹配年龄大于20的，或则为男的db.students.find({name:{$regex:"^a",$option:"$i"}});//模糊查询，以a开头不论大小写db.students.find(0.limit(5).skip(1)//跳过第一条数据开始显示，总共显示5条数据db。students.find().sort({age:1})//按年龄从小到大排序，1代表升序，-1代表降序$lt:<$gt:>$gte:<=$lte:>=$ne:！=

MongoDB Database Basics