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You can use $nin operator for this. To understand the concept, let us create a collection with the document. The query to create a collection with a document is as follows −> db.documentWithAParticularFieldValueDemo.insertOne( ... { ... ... "StudentId" : 101, ... "StudentDetails" : ... [ ... { ... "TheoryMarks": 78, ... "PracticalMarks": 91 ... }, ... { ... Read More
Dangling pointerDangling pointer is a pointer pointing to a memory location that has been freed (or deleted). There are different ways where Pointer acts as dangling pointerFunction CallThe pointer pointing to local variable becomes dangling when local variable is not static.int *show(void) { int n = 76; /* ... */ return &n; }OutputOutput of this program will be garbage address.De-allocation of memoryint main() { float *p = (float *)malloc(sizeof(float)); //dynamic memory allocation. free(p); //after calling free() p becomes a dangling pointer p = NULL; //now p no more a dangling pointer. }Variable goes ... Read More
Following is the syntax to get the embedded data in a MongoDB documentdb.yourCollectionName.find({}, {‘yourOuterKeyName.yourInnerKeyName:1}).pretty();Let us first create a collection with documents> db.embeddedCollectionDemo.insertOne( ... { ... "StudentName" : "Larry", ... "StudentDetails": { ... "Larry1234": {"ProjectName": "Student Web Tracker"}, ... "Larry7645": {"ProjectName": "Hospital Management System"}, ... "Larry9879": {"ProjectName": "Library Management System"}, ... ... } ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5c98a100330fd0aa0d2fe4c5") }Following is the query to display all documents from a collection> db.embeddedCollectionDemo.find().pretty();This ... Read More
To delete nth row in MySQL, use DELETE statement and work with subquery. Let us first create a table:mysql> create table DemoTable1 -> ( -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> StudentName varchar(100) -> ); Query OK, 0 rows affected (0.99 sec)Following is the query to insert some records in the table using insert command:mysql> insert into DemoTable1(StudentName) values('Larry'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1(StudentName) values('Sam'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable1(StudentName) values('Mike'); Query OK, 1 row affected (0.18 sec) mysql> ... Read More
In this Program we will basically find a feedback arc set which contains edges which when removed from the graph, graph becomes directed acyclic graph.AlgorithmBegin function checkCG(int n) : n: number of vertices. arr: struct graph variable. Initialize cnt = 0 and size = (n-1). For i = 0 to n-1 if (cnt == size) return 0 if (arr[i].ptr == NULL) Increase cnt. for j = 0 to n-1 while (arr[j].ptr ... Read More
In this program a random graph is generated for random vertices and edges. The time complexity of this program is O(v*e). Where v is the number of vertices and e is the number of edges.AlgorithmBegin Develop a function GenRandomGraphs(), with ‘e’ as the number of edges and ‘v’ as the number of vertexes, in the argument list. Assign random values to the number of vertex and edges of the graph, Using rand() function. Print the connections of each vertex, irrespective of the direction. Print “Isolated vertex” for the vertex having no ... Read More
The contains() method is used to search a value in Septet class.Let us first see what we need to work with JavaTuples. To work with Septet class in JavaTuples, you need to import the following package −import org.javatuples.Septet;Note − Steps to download and run JavaTuples program If you are using Eclipse IDE to run Septet Class in JavaTuples, then Right Click Project → Properties → Java Build Path → Add External Jars and upload the downloaded JavaTuples jar file.The following is an example −Exampleimport org.javatuples.Septet; public class Demo { public static void main(String[] args) { Septet ... Read More
To avoid the incorrect datetime value error, you can use the STR_TO_DATE() method.As we know the datetime format is YYYY-MM-DD and if you won’t insert in the same format, the error would get generated.Let us see what actually lead to this error. For this, let us create a new table. The query to create a table is as followsmysql> create table CorrectDatetimeDemo - > ( - > Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, - > ArrivalTime datetime - > ); Query OK, 0 rows affected (0.63 sec)The occurs when we try to include a ... Read More
This example describes how to use the HttpSession object to find out the creation time and the last-accessed time for a session. We would associate a new session with the request if one does not already exist.Example Live Demo Session Tracking Session Tracking Session info Value ... Read More
This example demonstrate about How to use toLowerCase () in Android textview.Step 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 button it will take data and Convert into lower letters.Step 3 − Add the following code to src/MainActivity.javapackage com.example.myapplication; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; ... Read More