Mongo DB增删改查命令
1列出并选用
1.1列出所有数据库
>showdbs local0.000GB myblog0.000GB
1.2使用某个数据库
>usemyblog switchedtodbmyblog
1.3列出所有集合
>showcollections articles replicationColletion sessions users wangduanduan
2插入数据insert(value)
//在已经存在的集合中插入数据
>db.users.insert({name:'hh',age:23})
Inserted1record(s)in43ms
//在不存在的集合中插入数据,集合不存在则自动创建集合并插入
>db.students.insert({name:'hh',age:23})
Inserted1record(s)in72ms
3查询find(option)
3.1查询集合里所有的文档
>db.users.find()
/*1*/
{
"_id":ObjectId("583e908453be942d0c5419dc"),
"login_name":"wangduanduan",
"password":"wrongage"
}
/*2*/
{
"_id":ObjectId("583ed2a5cc9a937db049616d"),
"login_name":"hh",
"password":"sdfsdf"
}
/*3*/
{
"_id":ObjectId("583fb2e9b12f8b7a7aa37572"),
"name":"wangduanduan",
"age":34.0
}
/*4*/
{
"_id":ObjectId("583fb707b12f8b7a7aa37573"),
"name":"hh",
"age":23.0
}
3.2按条件查询文档
>db.users.find({name:'wangduanduan'})
/*1*/
{
"_id":ObjectId("583fb2e9b12f8b7a7aa37572"),
"name":"wangduanduan",
"age":34.0
}
注意
//这是错的，查不到结果
>db.users.find({_id:'583fb2e9b12f8b7a7aa37572'})
Fetched0record(s)in1ms
//这是正确的
>db.users.find({_id:ObjectId('583fb2e9b12f8b7a7aa37572')})
/*1*/
{
"_id":ObjectId("583fb2e9b12f8b7a7aa37572"),
"name":"wangduanduan",
"age":34.0
}
3.3查询集合内文档的个数
>db.users.count() 4
3.4比较运算符
$gt:大于
$gte:大于等于
$lt:小于
$lte:小于等于
$ne:不等于
//查询用户里年龄大于30岁的人，其他条件以此类推
>db.user.find({age:{$gt:30}})
/*1*/
{
"_id":ObjectId("583fb2e9b12f8b7a7aa37572"),
"name":"wangduanduan",
"age":34.0
}
3.5逻辑运算符
3.5.1与
//查询名字是wangduanduan,age=34的用户
>db.users.find({name:'wangduanduan',age:34})
/*1*/
{
"_id":ObjectId("583fb2e9b12f8b7a7aa37572"),
"name":"wangduanduan",
"age":34.0
}
3.5.2$in或
//查询名字是wangduanduan,或hh的用户
>db.users.find({name:{$in:['wangduanduan','hh']}})
/*1*/
{
"_id":ObjectId("583fb2e9b12f8b7a7aa37572"),
"name":"wangduanduan",
"age":34.0
}
3.5.3$nin非
//查询名字不是wangduanduan或者hh的用户
>db.users.find({name:{$nin:['wangduanduan','hh']}})
/*1*/
{
"_id":ObjectId("583e908453be942d0c5419dc"),
"login_name":"wangduanduan",
"password":"wrongage"
}
/*2*/
{
"_id":ObjectId("583ed2a5cc9a937db049616d"),
"login_name":"hh",
"password":"sdfsdf"
}
3.6正则匹配
//查询名字是中含有duan的用户
>db.users.find({name:/duan/})
/*1*/
{
"_id":ObjectId("583fb2e9b12f8b7a7aa37572"),
"name":"wangduanduan",
"age":34.0
}
/*2*/
{
"_id":ObjectId("583fc919b12f8b7a7aa37575"),
"name":"wangduanduan",
"age":45.0
}
3.7大招$where
//返回含有login_name字段的文档
db.getCollection('users').find({$where:function(){
return!!this.login_name;
}})
4更新update();
4.1整体更新
>db.users.update({login_name:'wangduanduan'},{name:'heihei',age:34})
Updated1existingrecord(s)in116ms
4.2$set局部更新
//只是将用户年龄设置成101
>db.users.update({name:'wangduanduan'},{$set:{age:101}})
4.3$inc
//将用户年龄增加1岁，如果文档没有age这个字段，则会增加这个字段
>db.users.update({name:'wangduanduan'},{$inc:{age:1}})
4.3upsert操作
//如果查不到文档，则增加文档
>db.users.update({name:'nobody'},{$inc:{age:1}},true)
Updated1newrecord(s)in3ms
/*6*/
{
"_id":ObjectId("583fd20f2cfa6a4817c4171c"),
"name":"nobody",
"age":1.0
}
4.4批量更新
//upadate的第四个参数设置成true的时候，就会批量更新
>db.users.update({name:'wangduanduan'},{$set:{age:1891}},false,true)
5删除
//删除某些文档
db.person.remove({"name":"joe"})
//删除整个集合
db.person.remove()