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Yes, to display a database in the list, first create a database and add collection(s), else it won’t be visible in the list. After that, use the SHOW dbs command to display the database name in the list of databases.Following is the query to create a database −> use webcustomertracker; switched to db webcustomertrackerLet us first create a collection with documents −> db.first_Collection.insert({"Name":"Chris"}); WriteResult({ "nInserted" : 1 })Following is the query to display all documents from a collection with the help of find() method −> db.first_Collection.find();This will produce the following output −{ "_id" : ObjectId("5ce2760836e8b255a5eee94a"), "Name" : "Chris" }Following is ... Read More
Difference between for...in and for...of loopsBoth the loops iterate over something. The main difference between them is in what they iterate over.1) for...in loopThis loop iterates over enumerable properties of an object in an arbitrary order. It cares only about properties but not values.In the following example by using for...in loop the properties of the array are iterated. Since it is an array, Index is an important property so index of each and every element will be iterated and displayed in the output. In addition to indexes some inherited properties such as "inherProp2", "inherProp1" are also displayed.Example-1Live Demo ... Read More
For this, use BETWEEN operator in MySQL. Let us first create a table −mysql> create table DemoTable -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> Start int, -> End int -> ); Query OK, 0 rows affected (0.91 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Start, End) values(100, 200); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(Start, End) values(400, 500); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(Start, End) values(210, 350); Query OK, 1 row affected (0.11 sec)Display all ... Read More
In this section, we will see how we can get the sum of all odd prime factors of a number in an efficient way. There is a number say n = 1092, we have to get all factor of this. The prime factors of 1092 are 2, 2, 3, 7, 13. The sum of all odd factors is 3+7+13 = 23. To solve this problem, we have to follow this rule −When the number is divisible by 2, ignore that factor, and divide the number by 2 repeatedly.Now the number must be odd. Now starting from 3 to square root ... Read More
To use the sizeof(), we can take the value using a variable x, using &x, it will print the address of it. Now if we increase the value of &x then it may increase in different way. If only one byte is increased, that means it is character, if the increased value is 4, then it is int or float and so on. So by taking the difference between &x + 1 and &x, we can get the size of x.Here we will use macro as the datatype is not defined in the function. And one more thing, we are ... Read More
Use aggregate function SUM() along with OVER. Let us first create a table −mysql> create table DemoTable ( CustomerId int NOT NULL AUTO_INCREMENT PRIMARY KEY, CustomerValue int ); Query OK, 0 rows affected (0.64 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(CustomerValue) values(10); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(CustomerValue) values(20); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(CustomerValue) values(30); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable(CustomerValue) values(40); Query OK, 1 row affected (0.14 sec)Display all records ... Read More
To style code in a TextPane component use the setText() for text and work with HTML tags. For code, use the tag. Also, do not forget to set the content type to “text/html” −JTextPane pane = new JTextPane(); pane.setContentType("text/html");If you won’t set the content type, then the output will display all these HTML tags inside the JTextPane. Now, set the code inside −pane.setText(" #include ; using namespace std; main() {cout
This example demonstrate about How to get current foreground activity context 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 src/MyApp.javapackage app.tutorialspoint.com.sample ; import android.app.Activity ; import android.app.Application ; public class MyApp extends Application { private Activity mCurrentActivity = null; @Override public void onCreate () { super .onCreate() ; } public Activity getCurrentActivity () { return mCurrentActivity ; } public void setCurrentActivity ... Read More
To return documents of a collection without objectId, set _id:0. Let us first create a collection with documents −> db.returnDocumentWithoutObjectId.insertOne({"Name":"Carol", "Age":25}); { "acknowledged" : true, "insertedId" : ObjectId("5ce8ba6c78f00858fb12e8fa") } > db.returnDocumentWithoutObjectId.insertOne({"Name":"Sam", "Age":21}); { "acknowledged" : true, "insertedId" : ObjectId("5ce8ba6d78f00858fb12e8fb") } > db.returnDocumentWithoutObjectId.insertOne({"Name":"John", "Age":23}); { "acknowledged" : true, "insertedId" : ObjectId("5ce8ba6f78f00858fb12e8fc") }Following is the query to display all documents from a collection with the help of find() method −> db.returnDocumentWithoutObjectId.find();This will produce the following output −{ "_id" : ObjectId("5ce8ba6c78f00858fb12e8fa"), "Name" : "Carol", "Age" : 25 } { "_id" : ObjectId("5ce8ba6d78f00858fb12e8fb"), "Name" : "Sam", "Age" : ... Read More
_.size()_.Size() is from the underscore.js library of javascript. This is used to find the size of an array. One should make sure that before using this method one should use the CDN of the underscore.js to execute the code.syntax_.size(array);Example-1In the following example, a normal array is passed into _.size() method to get the size of the array.Live Demo var arr = [100, 62, 73, 534, 565]; document.write(_.size(arr)); Output5Example-2In the following example, an array that consists of object elements is sent into _.size() method to find the size.Live Demo ... Read More