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To understand this concept, we are using the data from table ‘Salary’ as follows −mysql> Select * from Salary; +--------+--------+ | Name | Salary | +--------+--------+ | Gaurav | 50000 | | Rahul | 40000 | | Ram | 45000 | | Raman | 45000 | +--------+--------+ 4 rows in set (0.00 sec) mysql> Select * from salary12345 order by salary DESC limit 1 offset 1; +-------+--------+ | name | Salary | +-------+--------+ | Raman | 45000 | +-------+--------+ 1 row in set (0.00 sec)
To convert an ArrayList to Array, use the ToArray() method in C#.Firstly, set an ArrayList −ArrayList arrList = new ArrayList(); arrList.Add("one"); arrList.Add("two"); arrList.Add("three");Now, to convert, use the ToArray() method −arrList.ToArray(typeof(string)) as string[];Let us see the complete code −Example Live Demousing System; using System.Collections; public class Program { public static void Main() { ArrayList arrList = new ArrayList(); arrList.Add("one"); arrList.Add("two"); arrList.Add("three"); string[] arr = arrList.ToArray(typeof(string)) as string[]; foreach (string res in arr) { Console.WriteLine(res); } } }Outputone two three
With the help of ALTER EVENT statement along with the ENABLE and DISABLE keyword, we can ENABLE and DISABLE the event. To illustrate it we are having the following example −Examplemysql> ALTER EVENT hello DISABLE; Query OK, 0 rows affected (0.00 sec)The above query will DISABLE the event named ‘Hello’ and the query below will enable it.mysql> ALTER EVENT hello ENABLE; Query OK, 0 rows affected (0.00 sec)
Static variables are used for defining constants because their values can be retrieved by invoking the class without creating an instance of it. Static variables can be initialized outside the member function or class definition. You can also initialize static variables inside the class definition.Example Live Demousing System; namespace StaticVarApplication { class StaticVar { public static int num; public void count() { num++; } public int getNum() { return num; } } class ... Read More
To understand this concept, we are using the data from table ‘emp_tbl’ as follows −mysql> Select * from emp_tbl; +--------+------------+ | Name | DOB | +--------+------------+ | Gaurav | 1984-01-17 | | Gaurav | 1990-01-17 | | Rahul | 1980-05-22 | | Gurdas | 1981-05-25 | | Naveen | 1991-04-25 | | Sohan | 1987-12-26 | +--------+------------+ 6 rows in set (0.00 sec) mysql> SELECT Name, SYSDATE(), DOB, DATEDIFF(SYSDATE(), DOB)/365 AS AGE from emp_tbl WHERE(DATEDIFF(SYSDATE(), DOB)/365)>30; +--------+---------------------+------------+---------+ | Name | SYSDATE() | DOB | AGE ... Read More
As we know that an event is automatically dropped when it is expired and we would not be able to see it from SHOW EVENTS statement. To change such kind of behavior we can use ON COMPLETION PRESERVE while creating the event. It can be understood from the following example −Examplemysql> Create table event_messages(ID INT NOT NULL PRIMARY KEY AUTO_INCREMENT, MESSAGE VARCHAR(255) NOT NULL, Generated_at DATETIME NOT NULL); Query OK, 0 rows affected (0.61 sec)The below query will create an event without the use of ON COMPLETION PRESERVE hence it would not be seen in the output of SHOW EVENTS ... Read More
Inheritance allows us to define a class in terms of another class, which makes it easier to create and maintain an application.When creating a class, instead of writing completely new data members and member functions, the programmer can designate that the new class should inherit the members of an existing class. This existing class is called the base class, and the new class is referred to as the derived class. A class can be derived from more than one class or interface, which means that it can inherit data and functions from multiple base classes or interfaces.Let us see an ... Read More
To understand this concept, we are using the data from table ‘Details_city’ as follows −mysql> Select * from details_city; +--------+--------+ | City1 | City2 | +--------+--------+ | Delhi | Nagpur | | Delhi | Mumbai | | Nagpur | Delhi | | Katak | Delhi | | Delhi | Katak | +--------+--------+ 5 rows in set (0.00 sec)Now, the following query will delete the reverse duplicate values from details_city table −mysql> Select a.city1,a.city2 from details_city a WHERE a.city1
To create a new file in C#, use the FileStream object.The following is the syntax −FileStream = new FileStream( , , , );Let us see an example for a file “test.dat”, which is created/ opened using File object −FileStream F = new FileStream("test.dat", FileMode.OpenOrCreate,FileAccess.ReadWrite);The following is an example −Exampleusing System; using System.IO; namespace FileIOApplication { class Program { static void Main(string[] args) { FileStream F = new FileStream("test.dat", FileMode.OpenOrCreate, FileAccess.ReadWrite); for (int i = 1; i
Since we cannot use the INTERSECT query in MySQL, we will use the EXIST operator to simulate the INTERSECT query. It can be understood with the help of the following example −ExampleIn this example, we are two tables namely Student_detail and Student_info having the following data −mysql> Select * from Student_detail; +-----------+---------+------------+------------+ | studentid | Name | Address | Subject | +-----------+---------+------------+------------+ | 101 | YashPal | Amritsar | History | | 105 | Gaurav | Chandigarh | Literature | | 130 | Ram ... Read More