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To iterate efficiently through an array of integers of unknown size in C# is easy. Let’s see how.Firstly, set an array, but do not set the size −int[] arr = new int[] { 5, 7, 2, 4, 1 };Now, get the length and iterate through an array using for loop −for (int i = 0; i< arr.Length; i++) { Console.WriteLine(arr[i]); }Let us see the complete example −Example Live Demousing System; public class Program { public static void Main() { int[] arr = new int[] { 5, 7, 2, 4, 1 }; // Length Console.WriteLine("Length:" + arr.Length); for (int i = 0; i < arr.Length; i++) { Console.WriteLine(arr[i]); } } }OutputLength:5 5 7 2 4 1
It can be done with the help of the following query −mysql> SELECT trigger_name,action_order FROM INFORMATION_SCHEMA.triggers WHERE TRIGGER_SCHEMA = 'query' ORDER BY event_object_table,action_timing,event_manipulation; +------------------------------+--------------+ | trigger_name | action_order | +------------------------------+--------------+ | studentdetail_before_update | 1 | | studentdetail_before_update2 | 2 | +------------------------------+--------------+ 2 rows in set (0.10 sec)The above result set shows the order of multiple triggers created on the same event and action time in the database ‘query’.
Firstly, add elements −IDictionary d = new Dictionary(); d.Add(1,97); d.Add(2,89); d.Add(3,77); d.Add(4,88);Now, get the keys −List myList = new List(d.Keys);To iterate −foreach (int k in myList) { Console.WriteLine("{0}, {1}", k, d[k]); }The following is an example −Example Live Demousing System; using System.Collections.Generic; public class Demo { public static void Main() { IDictionary < int, int > d = new Dictionary < int, int > (); d.Add(1, 97); d.Add(2, 89); d.Add(3, 77); d.Add(4, 88); List < int > myList = new List < int > (d.Keys); foreach(int k in myList) { Console.WriteLine("{0}, {1}", k, d[k]); } } }Output1, 97 2, 89 3, 77 4, 88
To concatenate two lists, use AddRange() method.Set the first list −var products1 = new List < string > (); products1.Add("Belts"); products1.Add("Tshirt"); products1.Add("Trousers");Set the second list −var products2 = new List < string > (); products2.Add("Footwear"); products2.Add("Electronics");To concatenate both the lists −products1.AddRange(products2);The following is the complete code −Example Live Demousing System.Collections.Generic; using System; namespace Demo { public static class Program { public static void Main() { var products1 = new List < string > (); products1.Add("Belts"); products1.Add("Tshirt"); products1.Add("Trousers"); ... Read More
Firstly, use the DirectoryInfo object −//creating a DirectoryInfo object DirectoryInfo mydir = new DirectoryInfo(@"d:\amit");Now, use the GetFiles() method to get all the files −FileInfo [] f = mydir.GetFiles();To get the list of files in a directory, try to run the following code −Exampleusing System; using System.IO; namespace Demo { class Program { static void Main(string[] args) { //creating a DirectoryInfo object DirectoryInfo mydir = new DirectoryInfo(@"d:\amit"); // getting the files in the directory, their names and size FileInfo [] f = mydir.GetFiles(); foreach (FileInfo file in f) { Console.WriteLine("File Name: {0} Size: {1}", file.Name, file.Length); } Console.ReadKey(); } } }
We must have SUPER privileges to create or destroy triggers with the help of a CREATE or DROP statement. Other than that if the triggered statements use OLD or NEW then there are some additional privileges as follows which we require −To assign the value of a column with SET NEW.column_name = value then we must have the UPDATE privilege for the column.To use NEW.column_name in an expression to refer to the new value of a column, we must have the SELECT privilege for the column.
To loop through all the values of enum, use the Enum.GetValues().Firstly, set an Enum −public enum Grade { A, B, C, D, E, F };Now, with foreach loop, you need to loop through Enum.GetValues(typeof(Grade)) −foreach (Grade g in Enum.GetValues(typeof(Grade))) { Console.WriteLine(g); }Here is the complete code −Example Live Demousing System; public class EnumExample { public enum Grade { A, B, C, D, E, F }; public static void Main() { foreach (Grade g in Enum.GetValues(typeof(Grade))) { Console.WriteLine(g); } } }OutputA B C D E F
While querying data from a MySQL table, we may get duplicate values from a column. With the help of the DISTINCT clause in the SELECT statement, we can get rid of duplicate data in the result set.SyntaxSELECT DISTINCT Columns FROM Table_name WHERE conditions;ExampleFor example, we have a table named ‘tender’ having the following columns −mysql> Select * from tender; +----------+--------------+--------------+-------+ | clientid | client_Fname | Client_Lname | value | +----------+--------------+--------------+-------+ | 100 | Mohan | Kumar | 60000 | | 101 | Sohan | Singh ... Read More
Check for the following conditions −For odd and even, check for the remainder when the number is divided by 2 −// checking for odd/ even if(n % 2 == 0) { Console.WriteLine("Even"); } else { Console.WriteLine("Odd"); }For positive, negative and checking whether a number is 0 or not −if (n < 0) { Console.WriteLine("Negative Number!"); } else if(n == 0) { Console.WriteLine("Zero"); } else { Console.WriteLine("Positive Number!"); }The following is the complete code:Example Live Demousing System; using System.Collections.Generic; public class Demo { public static void Main(string[] args) { int n = 19; ... Read More
We can destroy a trigger in two ways −Dropping a trigger explicitlyWith the help of the DROP statement, we can destroy a trigger explicitly. It can be understood with the help of the following example −mysql> DROP Trigger before_inser_studentage1; Query OK, 0 rows affected (0.05 sec)Dropping a trigger implicitlyA trigger will be destroyed implicitly if the table with which it is associated is destroyed or if the database which it is associated is destroyed.