Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Articles by karthikeya Boyini
Page 129 of 143
MySQL Order By date column and integer column, but specify ordering rules of integer column? Is it possible?
You can achieve this with the help of ORDER BY CASE statement. The syntax is as follows −SELECT *FROM yourTableName ORDER BY CASE yourIntegerColumnName1 WHEN 2 THEN 1 ELSE 0 END DESC ,yourDateColumnName ASC;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table OrderByCaseDemo -> ( -> Id int NOT NULL AUTO_INCREMENT, -> GroupId int, -> ArrivalDate date, -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (1.57 sec)Insert some records in the table using insert command. The query is as ...
Read MoreIterate through Quintet class in Java Tuples
You can iterate through Quintet class using a loop, like arrays in Java.Let us first see what we need to work with JavaTuples. To work with Quintet class in JavaTuples, you need to import the following package −import org.javatuples.Quintet;Note − Steps to download and run JavaTuples program If you are using Eclipse IDE to run Quintet 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.Quintet; public class Demo { public static void main(String[] args) { ...
Read MoreJava Program to get Temporal Queries precision
To get Temporal Queries precision, use the TemporalQuery interface with the precision() method of the TemporalQueries −TemporalQueryprecision = TemporalQueries.precision(); Get the precision for LocalDate: LocalDate.now().query(precision) Get the precision for LocalTime: LocalTime.now().query(precision) Get the precision for YearMonth: YearMonth.now().query(precision) Get the precision for Year: Year.now().query(precision)Exampleimport java.time.LocalDate; import java.time.LocalDateTime; import java.time.LocalTime; import java.time.Year; import java.time.YearMonth; import java.time.temporal.TemporalQueries; import java.time.temporal.TemporalQuery; import java.time.temporal.TemporalUnit; public class Demo { public static void main(String[] args) { TemporalQueryprecision = TemporalQueries.precision(); System.out.println("TemporalQueries precision..."); System.out.println(LocalDate.now().query(precision)); System.out.println(LocalTime.now().query(precision)); System.out.println(LocalDateTime.now().query(precision)); System.out.println(YearMonth.now().query(precision)); System.out.println(Year.now().query(precision)); ...
Read MoreChange max_heap_table_size value in MySQL?
The max_heap_table_size is a system variable that has both read/write property.Initially, max_heap_table_size has size 16 MB. First, check the value of max_heap_table_size, which is in bytes.The query is as follows −mysql> select @@max_heap_table_size;The following is the output −+-----------------------+ | @@max_heap_table_size | +-----------------------+ | 16777216 | +-----------------------+ 1 row in set (0.00 sec)Now let us how the value 16777216 byte = 16 MB −1 MB = 1024KB 1KB = 1024 Bytes 1MB = 1024*1024 bytes. To convert 16777216 byte to MB you need to divide 1024*1024. =16777216/(1024*1024) =16777216/1048576 ...
Read MoreHow to get number of quarters between two dates in Java
Let’s say we have the following two dates −LocalDate.of(2019, 3, 20); LocalDate.of(2019, 10, 25);To get the number of quarters between the above two dates, use the QUARTER_YEARS −IsoFields.QUARTER_YEARS.between(LocalDate.of(2019, 3, 20),LocalDate.of(2019, 10, 25));Exampleimport java.time.LocalDate; import java.time.temporal.IsoFields; public class Demo { public static void main(String[] args) { long quarters = IsoFields.QUARTER_YEARS.between(LocalDate.of(2019, 3, 20), LocalDate.of(2019, 10, 25)); System.out.println("Quarters between the two dates = " + quarters); } }OutputQuarters between the two dates = 2
Read MoreRename all tables and columns to lower case in MySQL?
You can achieve this with the help of INFORMATION_SCHEMA.COLUMNS. The syntax is as follows −SELECT CONCAT('ALTER TABLE ', TABLE_NAME, ' CHANGE `', COLUMN_NAME, '` `', LOWER(COLUMN_NAME), '` ', COLUMN_TYPE, ';') AS anyAliasName FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = ‘yourDatabaseName’;Now use the database which has two tables. The database name is as follows “bothinnodbandmyisam”. This database is having the following tables −employeestudentThe description of the employee table is as follows −mysql> desc employee;The following is the output. Let’s say we have the following columns in the employee table which are not in lowercase −+--------------+-------------+------+-----+---------+-------+ | Field | Type ...
Read MoreCreate Pair Tuple using with() method in Java
You can also create a Pair Tule in Java using the with() method.Let us first see what we need to work with JavaTuples. To work with Pair class in JavaTuples, you need to import the following package −import org.javatuples.Pair;Note − Steps to download and run JavaTuples program If you are using Eclipse IDE to run Pair 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 to create Pair Tuple using with() method −import org.javatuples.Pair; public class Demo { public static ...
Read MoreAs HTTP is a stateless then how to maintain the session between web browser and web server?
HTTP is a "stateless" protocol which means each time a client retrieves a Webpage, the client opens a separate connection to the Web server and the server automatically does not keep any record of previous client request.Maintaining Session Between Web Client And ServerLet us now discuss a few options to maintain the session between the Web Client and the Web Server −CookiesA webserver can assign a unique session ID as a cookie to each web client and for subsequent requests from the client they can be recognized using the received cookie.This may not be an effective way as the browser ...
Read MoreInsert default into not null column if value is null in MySQL?
You can use IFNULL() property or simple IF() with IS NULL property. The syntax is as follows −INSERT INTO yourTableName(yourColumnName1, yourColumnName2) VALUES('yourValue’', IF(yourColumnName1 IS NULL, DEFAULT(yourColumnName2), 'yourMessage'));To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table Post -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> UserName varchar(10), -> UserPostMessage varchar(50) NOT NULL DEFAULT 'Hi Good Morning !!!' -> ); Query OK, 0 rows affected (0.67 sec)Now you can ...
Read MoreCreate Pair Tuple from another collection in Java
Use the fromCollection() method to create a Pair Tuple from another collection, for example, List.Let us first see what we need to work with JavaTuples. To work with Pair class in JavaTuples, you need to import the following package −import org.javatuples.Pair;Note − Steps to download and run JavaTuples program If you are using Eclipse IDE to run Pair 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.Pair; import java.util.*; public class Demo { public static void main(String[] args) ...
Read More