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MongoDB语法与现有关系型数据库SQL语法比较

时间:2021-07-01 10:21:17 帮助过:4人阅读

"mycol"].find({},{_id:0,name:1}) # 第一个参数为条件,第二个参数为显示结果设置

db["mycol"].inseret({"key":"value",title:"tutorial",name:"jkmiao"})
 
MongoDB语法与现有关系型数据库SQL语法比较
MongoDB语法                                  MySql语法

db.test.find({name:foobar})<==> select * from test where name=foobar

db.test.find()                            <==> select *from test

db.test.find({ID:10}).count()<==> select count(*) from test where ID=10

db.test.find().skip(10).limit(20)<==> select * from test limit 10,20

db.test.find({ID:{$in:[25,35,45]}})<==> select * from test where ID in (25,35,45)

db.test.find().sort({ID:-1})  <==> select * from test order by IDdesc

db.test.distinct(name,{ID:{$lt:20}})  <==> select distinct(name) from testwhere ID<20 

db.test.group({key:{name:true},cond:{name:foo},reduce:function(obj,prev){prev.msum+=obj.marks;},initial:{msum:0}})  <==> select name,sum(marks) from testgroup by name
 

db.test.find(this.ID<20,{name:1})  <==> select name from test whereID<20
 

db.test.insert({name:foobar,age:25})<==>insertinto test (name,age) values(foobar,25)

 

db.test.remove({})                        <==> delete * from test

db.test.remove({age:20})            <==> delete test where age=20

db.test.remove({age:{$lt:20}})   <==> elete test where age<20

db.test.remove({age:{$lte:20}})  <==> delete test where age<=20

db.test.remove({age:{$gt:20}})  <==> delete test where age>20

db.test.remove({age:{$gte:20}})<==> delete test where age>=20

db.test.remove({age:{$ne:20}})  <==> delete test where age!=20

 

db.test.update({name:foobar},{$set:{age:36}})<==> update test set age=36 where name=foobar

db.test.update({name:foobar},{$inc:{age:3}})<==> update test set age=age+3 where name=foobar

 

MongoDB语法与现有关系型数据库SQL语法比较

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