Change Delimiter for Creating a Trigger in MySQL

Swarali Sree
Updated on 22-Jun-2020 12:15:45

615 Views

As we know that in MySQL we use the delimiter semicolon (;) to end each statement. The semicolon is the by default delimiter in MySQL. We need to change the delimiter, while creating a trigger, to tell MySQL that this is not the end of our trigger statement because we can use multiple statements in the trigger. We can change the delimiter temporarily by DELIMITER // statement to change the delimiter from Semicolon (;) to two back-slash (//). After this MySQL would know that the triggering statement only ends when it encounters a two back-slash (//). Following is an example ... Read More

Insert Item in ArrayList in C#

karthikeya Boyini
Updated on 22-Jun-2020 12:14:40

537 Views

To insert an item in an already created ArrayList, use the Insert() method.Firstly, set elements −ArrayList arr = new ArrayList(); arr.Add(45); arr.Add(78); arr.Add(33);Now, let’s say you need to insert an item at 2nd position. For that, use the Insert() method −// inserting element at 2nd position arr.Insert(1, 90);Let us see the complete example −Example Live Demousing System; using System.Collections; namespace Demo {    public class Program {       public static void Main(string[] args) {          ArrayList arr = new ArrayList();          arr.Add(45);          arr.Add(78);       ... Read More

Check Tables of Databases Other Than Current Database

Giri Raju
Updated on 22-Jun-2020 12:14:06

138 Views

With the help of following MySQL command, we can check the tables of a database other than the database we are currently using −Show Tables from Database_name;For example, the following query would display the list of tables from a database named ‘gaurav’ when currently we are using a database named ‘new’ −mysql> use new; Database changed mysql> show tables from gaurav; +--------------------+ | Tables_in_tutorial | +--------------------+ | testing            | | employee           | | tender             | | Ratelist           | +--------------------+ 4 rows in set (0.00 sec)

Instantiate a Class in C#

Samual Sam
Updated on 22-Jun-2020 12:13:46

5K+ Views

Use the new operator to instantiate a class in C#.Let’s say our class is Line. Instantiation will create a new object as shown below −Line line = new Line();Using the object, you can now call the method −line.setLength(6.0);Let us see the example −Example Live Demousing System; namespace LineApplication {    class Line {       private double length; // Length of a line       public Line() {          Console.WriteLine("Object is being created");       }       public void setLength( double len ) {          length = len; ... Read More

Iterate Any Map in C#

karthikeya Boyini
Updated on 22-Jun-2020 12:13:07

2K+ Views

C# has no built-in Math type. For the same, use a Dictionary.Firstly, create a Dictionary −Dictionary d = new Dictionary(); d.Add("keyboard", 1); d.Add("mouse", 2);Get the keys −var val = d.Keys.ToList();Now, use the foreach loop to iterate over the Map −foreach (var key in val) {    Console.WriteLine(key); }To iterate it, try to run the following code −Example Live Demousing System; using System.Collections.Generic; using System.Linq; class Program {    static void Main() {       Dictionary d = new Dictionary();       d.Add("keyboard", 1);       d.Add("mouse", 2);       // get keys   ... Read More

Iterate Efficiently Through an Array of Integers in C#

Samual Sam
Updated on 22-Jun-2020 12:12:32

541 Views

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

See Information on Triggers Order for Same Event in SQL

karthikeya Boyini
Updated on 22-Jun-2020 12:12:28

105 Views

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’.

Iterate Over a C# Dictionary

karthikeya Boyini
Updated on 22-Jun-2020 12:11:55

507 Views

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

Join or Concatenate Two Lists in C#

Samual Sam
Updated on 22-Jun-2020 12:11:06

3K+ Views

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

List All Files in a Directory Using C#

karthikeya Boyini
Updated on 22-Jun-2020 12:09:50

423 Views

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();       }    } }

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