05 mongodb summary of various column operations

Catalog ： The basic chapter （ Can solve the problem of 80 The problem of ）
01 MongoDB Overview 、 Application scenarios 、 Download mode 、 Connection mode and development history, etc

02 MongoDB data type 、 Key concepts and shell Commonly used instructions

03 MongoDB Various additions to documents 、 to update 、 Delete operation summary

04 MongoDB Various query operations And summary of aggregation operations

05 MongoDB Summarize the various operations of the column

python3 operation MongoDB Various cases of

One . Change column names

Case study 1： modify age by 31 Of the column address Change the name of the column to address2, Only one record will be modified .

db.person.update({
    age:31},{
    $rename:{
    address:'address2'}})

Case study 2： name For Zhang San's address Change the name of the column to address2, All records that meet the conditions will be modified .

db.person.update({
    name:' Zhang San '},{
    $rename:{
    address:'address2'}},{
    multi:true})

Two . Adding or deleting Columns

Update specific fields ：

db.game.update({
    "_id": 123}, {
     "$set": {
    "count": 10000}})

#  amount to sql Medium 
update game set count = 10000 where _id = 123;

Delete specific fields ：

db.game.update({
    "_id":123}, {
    "$unset": {
    "author":1}})

Case study 1： Add column name as name The value of is the column of sheet three , Only one more .

db.person.update({
    name:' Zhang San '},{
    $set:{
    age:''}})　

Case study 2： Add a column to the set age, The default is empty. , This column will be added to all documents ：

db.person.update({
    name:' Zhang San '},{
    $set:{
    age:''}}, {
    multi:true})　

Case study 3： Delete column named name The value of is the column of sheet three , Column names and column values are deleted , Only one item will be deleted .

db.person.update({
    name:' Zhang San '},{
    $unset:{
    age:''}})

Case study 4： Delete column named name The value of is the column of sheet three , Column names and column values are deleted , Those that meet the conditions will be deleted .

db.person.update({
    name:' Zhang San '},{
    $unset:{
    age:''}},{
    multi:true})

3、 ... and . Update and insert a column field

3.1 $inc: To increase or decrease

The corresponding field must be a number , And the increasing or decreasing value must also be a number .

Case study 1： Give a column self growth $inc ,_id by 1 The record of ,age increase 1

#  Every time age all 10
db.person.update({
    _id:1},{
    $inc: {
    age:10}})　　　

Case study 2： change 1 Bar record

db.person.update({
    name:' Zhang San '},{
    $inc:{
    age:10}})

Case study 3： Change all records that meet the conditions

db.person.update({
    name:' Zhang San '},{
    $inc:{
    age:10}},{
    multi:ture})

3.2 Array append

$push Array append ,

Case study 1： Add an element

db.game.update({
    "_id": 123}, {
     "$push": {
    "score": 123}})

Case study 2： Add multiple elements

db.game.update({
    "_id": 123}, {
    "$push": {
    "score": [12,123]}})

notes ： The append field must be an array . If the array field does not exist , It will be added automatically , Then add .

3.3 Add more than one element at a time

$pushAll Add more than one element at a time

db.game.update({
    "_id": 123}, {
    "$pushAll": {
    "score": [12,123]}})

3.4 Appending non repeating elements

$addToSet： Appending non repeating elements , Like a collection Set, Increase only if the value is not in the element ：

db.game.update({
    "_id": 123}, {
    "$addToSet": {
    "score": 123}})

3.5 Other field operations

Case study 1： without _id by 4 The record of , The insert

db.person.update({
    _id:4},{
    $set: {
    name:' Li Si ',class:' Class three ',score:90}},{
    upsert:true})

#  Inserted data results 
{
     "_id" : 4, "name" : " Li Si ", "class" : " Class three ", "score" : 90 }

Case study 2： If the row is not updated , Insert additional columns ：$setOnInsert,upsert:true

db.person.update({
    _id:5},{
    $setOnInsert:{
    name:' Wang Wu ',like:'football'}},{
    upsert:true})

#  After execution , The following records are added to the database ：
{
     "_id" : 5, "like" : "football", "name" : " Wang Wu " }

#  If there is _id  by  5  The record of , Execute the following statement , There will be no impact , No new , It won't change .
db.person.update({
    _id:5},{
    $setOnInsert:{
    name:' Wang Wu ',like:'football',height:178}},{
    upsert:true});

Case study ： If the row is not updated , Insert additional columns ：$setOnInsert,upsert:true

db.person.update({
    _id:5},{
    $setOnInsert:{
    name:' Wang Wu ',like:'football'}},{
    upsert:true})

#  If there is _id  by 5 The record of , Execute the following statement , There will be no impact , It will not be added or modified 
db.person.update({
    _id:5},{
    $setOnInsert:{
    name:' Wang Wu ',like:'football',height:178}},{
    upsert:true})

Four . Remove elements

4.1 Delete an element

$pop Remove elements , Only one element in the array can be deleted at a time ,1 Means delete the last ,-1 To delete the first .

#  Delete the last element 
db.game.update({
    "_id": 123}, {
    "$pop": {
    "score": 1}})

#  Delete first element 
db.game.update({
    "_id": 123}, {
    "$pop": {
    "score": -1}})

Case study ： Delete specific elements

db.game.update({"_id": 123}, {"$pull": {"score": 123}})

4.2 Delete specific elements

$pull Delete specific elements

#  Delete array score The internal value is equal to 123 The elements of .
db.game.update({
    "_id": 123}, {
    "$pull": {
    "score": 123}})

4.3 Delete multiple specific elements

$pullAll Delete specific elements

#  Delete the values in the array equal to 123 or 12 The elements of .
db.game.update({
    "_id": 123}, {
    "$pullAll": {
    score: [123,12]}})

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