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To open a plain text file, use the StreamReader class. The following opens a file for reading −StreamReader sr = new StreamReader("d:/new.txt")Now, display the content of the file −while ((line = sr.ReadLine()) != null) { Console.WriteLine(line); }Here is the code −Example Live Demousing System; using System.IO; namespace FileApplication { class Program { static void Main(string[] args) { try { using (StreamReader sr = new StreamReader("d:/new.txt")) { string line; // ... Read More
Here, we are reading two different files −Reading text file −Example Live Demousing System; using System.IO; namespace FileApplication { class Program { static void Main(string[] args) { try { using (StreamReader sr = new StreamReader("d:/new.txt")) { string line; // Read and display lines from the file until // the end of the file is reached. while ((line ... Read More
As we know that recurring event means that it will be executed after regular time of interval and expires at the specified time. To illustrate the creation of such kind of events we are using the following example in which we are creating an event which will execute after every minute and expires after one hour −mysql> CREATE EVENT testing_event10 ON SCHEDULE EVERY 1 MINUTE STARTS CURRENT_TIMESTAMP ENDS CURRENT_TIMESTAMP + INTERVAL 1 HOUR DO INSERT INTO event_message(message, generated_at) Values('Recrring evnts', NOW()); Query OK, 0 rows affected (0.00 sec) mysql> Select * from event_message; +----+----------------+---------------------+ | ID | MESSAGE ... Read More
To open a hidden file, first make it visible. You can do this by removing the hidden attribute set on it −FileInfo file= new FileInfo(Environment.CurrentDirectory + @"\myFile.txt"); file.Attributes &= ~FileAttributes.Hidden;Now treat it as a normal text file and open it. Read the content −using (StreamReader sr = new StreamReader("myFile.txt")) { string line; while ((line = sr.ReadLine()) != null) { Console.WriteLine(line); } }After reading, set the attribute as hidden again to hide the file −file.Attributes |= FileAttributes.Hidden;
To understand this concept, we are using the data from table ‘Information’ as follows −mysql> Select * from Information; +----+---------+ | id | Name | +----+---------+ | 1 | Gaurav | | 2 | Ram | | 3 | Rahul | | 4 | Aarav | | 5 | Aryan | | 6 | Krishan | +----+---------+ 6 rows in set (0.00 sec)Now, the query below will fetch the alternate odd-numbered records from the above table ‘Information’ −mysql> Select id,Name from information group by id having mod(id,2) = 1; +----+--------+ | id | Name | +----+--------+ | 1 | Gaurav | | 3 | Rahul | | 5 | Aryan | +----+--------+ 3 rows in set (0.09 sec)
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