Characters Not Allowed in MongoDB Field Names

Smita Kapse
Updated on 29-Jun-2020 16:00:38

792 Views

Do not use $ symbol or period (.) because these characters are not allowed for MongoDB field names. The field shouldn’t start with $.Here is an example of the allowed characters −> db.charactersAllowedDemo.insertOne({"Employee Name" : "John"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c7fefbc8d10a061296a3c6d") }Display all documents from a collection with the help of find() method. The query is as follows −> db.charactersAllowedDemo.find().pretty();The following is the output −{    "_id" : ObjectId("5c7fefbc8d10a061296a3c6d"),    "Employee Name" : "John" }

Remove Duplications from ArrayList Using TreeSet for ListView in Android

karthikeya Boyini
Updated on 29-Jun-2020 15:57:06

154 Views

This example demonstrate about How to remove duplications from arraylist using treeset for listview in AndroidStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.                                 In the above code, we have taken name as Edit text, when user click on save button it will store the data into arraylist. Click on refresh button to get the changes of listview.Step ... Read More

Remove Duplications from ArrayList Using LinkedHashSet for ListView in Android

Samual Sam
Updated on 29-Jun-2020 15:55:58

152 Views

This example demonstrate about How to remove duplications from arraylist using linked hashset for listview in AndroidStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.                                 In the above code, we have taken name as Edit text, when user click on save button it will store the data into arraylist. Click on refresh button to get the changes of ... Read More

Remove Duplications from ArrayList for ListView in Android

karthikeya Boyini
Updated on 29-Jun-2020 15:55:23

172 Views

This example demonstrate about How to remove duplications from arraylist for listview in AndroidStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.                                 In the above code, we have taken name as Edit text, when user click on save button it will store the data into arraylist. Click on refresh button to get the changes of listview.Step 3 − Add ... Read More

Insert Element to Linked List for ListView in Android

Samual Sam
Updated on 29-Jun-2020 15:54:26

363 Views

This example demonstrate about How to insert element to linked list for listview in AndroidStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.                                 In the above code, we have taken name as Edit text, when user click on save button it will store the data into array list. Click on refresh button to get the changes of listview.Step ... Read More

Insert Element to ArrayList for ListView in Android

karthikeya Boyini
Updated on 29-Jun-2020 15:53:41

2K+ Views

This example demonstrate about How to insert element to arraylist for listview in AndroidStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.                                 In the above code, we have taken name as Edit text, when user click on save button it will store the data into arraylist. Click on refresh button to get the changes of listview.Step 3 − Add ... Read More

Delete Element from Linked List for ListView in Android

Samual Sam
Updated on 29-Jun-2020 15:52:32

485 Views

This example demonstrate about How to delete element from linked list for listview in AndroidStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.                                       In the above code, we have taken name as Edit text, when user click on save button it will store the data into arraylist. Click on delete button to delete the ... Read More

Delete Element from ArrayList for ListView in Android

karthikeya Boyini
Updated on 29-Jun-2020 15:51:47

2K+ Views

This example demonstrate about How to delete element from arraylist for listview in AndroidStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.                                       In the above code, we have taken name as Edit text, when user click on save button it will store the data into arraylist. Click on delete button to delete the record ... Read More

Delete All Elements from Linked List for ListView in Android

Samual Sam
Updated on 29-Jun-2020 15:50:38

144 Views

This example demonstrate about How to delete all elements from linked list for listview in AndroidStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.                                             In the above code, we have taken name as Edit text, when user click on save button it will store the data into arraylist. Click on ... Read More

Delete All Elements from ArrayList for ListView in Android

karthikeya Boyini
Updated on 29-Jun-2020 15:48:40

1K+ Views

This example demonstrate about How to delete all elements from arraylist for listview in AndroidStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.                                             In the above code, we have taken name as Edit text, when user click on save button it will store the data into arraylist. Click on delete ... Read More

Advertisements