Mongodb/ document operation

06 Inserted into the document

Insert multiple

db.stus.insert({ object 2},{ object 3});

 Will be generated according to the timestamp id
 You can also define 

Import the development environment data into the production environment

Data may be duplicated Add to each document id attribute , Make sure it's unique .

7 Query the document

db.status.find({
    _id:"hello"});
 Query all eligible documents ;


db.stus.find({
    age:16,name:"xians"});

 There are many ways of conditional transmission .
    ;
db.collection.findOne();  // Query the first eligible document 
find()   It returns an array ;

db.collection.find({
    }).count();// Query the number of all results 

8 Modify the document

db.stus.update({name:" The sand monk "},{age:33});

Partial modification

db.stus.update(
    {
    "_id":ObjectId("hsfhkdh")},
    {
    $set:{
    
        name:" Pig eight quit ",
        address:" Liusha River "
    }}
)

$unset

db.stus.update(
    {"_id":ObjectId("hsfhkdh")},
    {$unset:{
        name:" Pig eight quit "
    }}
)

db.collection.updateMany()  // Modify multiple qualified documents at the same time .

db.collection.updateOne()  // Modify a qualified document 

update // Only one is changed by default 

modify update The default attribute of can be modified at the same time

db.stus.update(
	{"name":" solve "}
    {$set:{
        name:" Pig eight quit "
    }},
    {multi:true}
)

9 Delete the document

remove Delete multiple by default , Delete only one , You need to set the parameter to true;

db.stus.remove({_id:"hello"},true);

// If you pass an empty parameter , Delete all 
// Empty the set , Slightly poor performance . First match , And then delete . It is more convenient to delete the set directly 
db.stus.remove({});

Delete the collection

db.stus.drop();

Generally, database data will not be deleted , Just add a parameter , To indicate whether the data has been deleted ,.

db.updateOne({name="ts"},{$set:{idDel:1}});
db.stus.find({idDel:0})