Alter Data Type of a MySQL Table's Column

Samual Sam
Updated on 30-Jul-2019 22:30:25

201 Views

You can use modify command for this. Let us first us create a table.mysql> create table DemoTable (    StudentId varchar(200) not null,    StudentName varchar(20),    StudentAge int,    StudentAddress varchar(20),    StudentCountryName varchar(20) ); Query OK, 0 rows affected (0.73 sec)Now check the description of table.mysql> desc DemoTable;This will produce the following output −+--------------------+--------------+------+-----+---------+-------+ | Field              | Type         | Null | Key | Default | Extra | +--------------------+--------------+------+-----+---------+-------+ | StudentId          | varchar(200) | NO   |     | NULL    |     ... Read More

ByteBuffer asIntBuffer Method in Java

karthikeya Boyini
Updated on 30-Jul-2019 22:30:25

116 Views

A view of the ByteBuffer can be created as an IntBuffer using the asIntBuffer() method in the class java.nio.ByteBuffer. This method requires no parameters and it returns an int buffer as required. This buffer reflects the changes made to the original buffer and vice versa.A program that demonstrates this is given as follows −Example Live Demoimport java.nio.*; import java.util.*; public class Demo {    public static void main(String[] args) {       int n = 50;       try {          ByteBuffer bufferB = ByteBuffer.allocate(n);          IntBuffer bufferI = bufferB.asIntBuffer();       ... Read More

Use the Conditional Operator in C/C++

Chandu yadav
Updated on 30-Jul-2019 22:30:25

306 Views

This conditional operator is also known as the Ternary Operator. This operator has three phase.Exp1 ? Exp2 : Exp3;where Exp1, Exp2, and Exp3 are expressions. Notice the use and placement of the colon. The value of a ? expression is determined like this: Exp1 is evaluated. If it is true, then Exp2 is evaluated and becomes the value of the entire ? expression. If Exp1 is false, then Exp3 is evaluated and its value becomes the value of the expression.The ? is called a ternary operator because it requires three operands and can be used to replace if-else statements, which ... Read More

Update Field in Exact Element Array in MongoDB

Krantik Chavan
Updated on 30-Jul-2019 22:30:25

289 Views

You can update the in exact element array in MongoDB with the help of below statement. The syntax is as follows:{"yourArrayDocumentName.$.yourNestedArrayDocument.yourPosition":"yourValue"}});To understand the above syntax, let us create a collection with some documents. The query to create a collection with document is as follows:> db.updateExactField.insertOne({"ActorId":1, "ActorDetails":[{"ActorName":"Johnny Depp", "MovieList": ["The Tourist", "Public Enemy"]}, ... {"ActorName":"Chris Evans", "MovieList":["Captain America", "Avengers"]}]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c6d7f63f2db199c1278e7f1") }Now you can display documents from a collection with the help of find() method. The query is as follows:> db.updateExactField.find().pretty();The following is the output:{    "_id" : ObjectId("5c6d7f63f2db199c1278e7f1"),    "ActorId" : 1,   ... Read More

Explain HTTP Headers in Simple Terms in JSP Context

George John
Updated on 30-Jul-2019 22:30:25

178 Views

When a Web server responds to an HTTP request, the response typically consists of a status line, some response headers, a blank line, and the document. A typical response looks like this −HTTP/1.1 200 OK Content-Type: text/html Header2: ... ... HeaderN: ... (Blank Line) ... ... The status line consists of the HTTP version (HTTP/1.1 in the example), a status code (200 in the example), and a very short message corresponding to the status code (OK in the example).Following is ... Read More

Concat Two or More Columns with Separator in Android SQLite

Vrundesha Joshi
Updated on 30-Jul-2019 22:30:25

180 Views

Before getting into example, we should know what sqlite data base in android is. SQLite is an open source SQL database that stores data to a text file on a device. Android comes in with built in SQLite database implementation. SQLite supports all the relational database features. In order to access this database, you don't need to establish any kind of connections for it like JDBC, ODBC etc.This example demonstrate about How to concat two or more columns with separator in Android sqlite.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill ... Read More

LongStream Average Method in Java

Arjun Thakur
Updated on 30-Jul-2019 22:30:25

492 Views

The average() method of the LongStream class in Java returns an OptionalDouble describing the arithmetic mean of elements of this stream, or an empty optional if this stream is empty.The syntax is as follows.OptionalDouble average()Here, OptionalDouble is a container object which may or may not contain a double value.To use the LongStream class in Java, import the following package.import java.util.stream.LongStream;Create LongStream and add elements.LongStream longStream = LongStream.of(100L, 150L, 180L, 200L, 250L, 300L, 500L);Get the average of the elements in the stream.OptionalDouble res = longStream.average();The following is an example to implement LongStream average() method in Java.Example Live Demoimport java.util.*; import java.util.stream.LongStream; public ... Read More

Performance Difference Between i++ and ++i in C++

Nitya Raut
Updated on 30-Jul-2019 22:30:25

912 Views

There is a big distinction between the suffix and prefix versions of ++.In the prefix version (i.e., ++i), the value of i is incremented, and the value of the expression is the new value of i. So basically it first increments then assigns a value to the expression.In the postfix version (i.e., i++), the value of i is incremented, but the value of the expression is the original value of i. So basically it first assigns a value to expression and then increments the variable.Let's look at some code to get a better understanding.Example Code#include using namespace std; int main() ... Read More

MySQL Query to Group By Multiple Columns

Ankith Reddy
Updated on 30-Jul-2019 22:30:25

816 Views

You can use IF() to GROUP BY multiple columns. To understand the concept, let us create a table. The query to create a table is as followsmysql> create table MultipleGroupByDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> CustomerId int,    -> ProductName varchar(100)    -> ); Query OK, 0 rows affected (0.59 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into MultipleGroupByDemo(CustomerId, ProductName) values(1000, 'Product-1'); Query OK, 1 row affected (0.20 sec) mysql> insert into MultipleGroupByDemo(CustomerId, ProductName) values(1001, 'Product-2'); Query OK, 1 row affected (0.18 ... Read More

Getting a Subvector from a Vector in C++

Samual Sam
Updated on 30-Jul-2019 22:30:25

5K+ Views

This is a C++ program for getting a subvector from a vector in C++AlgorithmBegin   Declare s as vector s(vector const &v, int m, int n) to    initialize start and end position of vector to constructor.       auto first = v.begin() + m.         auto last = v.begin() + n + 1.       Declare a variable vector of vector type.          Pass the value of first and last position of vector.       Return vector.    Declare a template T.    Declare a function show().       ... Read More

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