You can use $pull operator for this. Let us first create a collection with documents. Here, we have also added an empty object −> db.removeEmptyObjectsDemo.insertOne(    {       "_id" :101,       "LoginDate" :new ISODate(),       "UserDetails" : [          {   ... Read More

You can use group_concat() along with concat() to concatenate all values of a single column. Let us first create a table −mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, FirstName varchar(20) ); Query OK, 0 rows affected (0.73 sec)Insert some records ... Read More

Let us first create a collection with documents −> db.updateArrayElementDemo.insertOne(    {       "UserDetails":       [          {             "UserName":"Chris",             "UserAge":23          }       ]    } ... Read More

To update boolean value, you can use SET. Let us first create a table −mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, isMarried boolean    ); Query OK, 0 rows affected (0.58 sec)Insert some records in the table using insert command −mysql> insert into ... Read More

To request location Permission we will be using Apple’s CLLocationManager class. You use instances of this class to configure, start, and stop the Core Location services.You can read more about CLLocationManager class here. https://developer.apple.com/documentation/corelocation/cllocationmanageriOS apps can support one of two levels of location access.While using the app − The app can ... Read More

You can use find() for this. Let us first create a collection with documents −> db.findDocumentsDemo.insertOne(    {       _id: 101,       "ProductDetails": [          { "ProductValue":100 },          { "ProductValue":120 }       ]    } ); { ... Read More

For performing mathematical operations and working with conditions, you can consider CASE statement. Let us first create a table −mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    FruitName varchar(100),    FruitPrice int    ); Query OK, 0 rows affected (0.26 sec)Insert some records ... Read More

To convert a field to an array, use $set operator. Let us first create a collection with documents −> db.convertAFieldToAnArrayDemo.insertOne({"StudentSubject":"MongoDB"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5ce92d7778f00858fb12e91d") }Following is the query to display all documents from a collection with the help of find() method −> db.convertAFieldToAnArrayDemo.find();This will produce ... Read More

You need to follow some steps to add a new column after a specific column and defining default value. In order to achieve this, you need to use ALTER command. Let us first create a table −mysql> create table DemoTable    (    StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, ... Read More

To update a single list item, use positional operator($). Let us first create a collection with documents −> db.updateASingleListDemo.insertOne({ _id:1, "EmployeeName":"Chris", "EmployeeDetails": [ {"EmployeeId":"EMP-101", "EmployeeSalary": 18999 }] }); { "acknowledged" : true, "insertedId" : 1 }Following is the query to display all documents from a collection with the help of ... Read More