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Articles by karthikeya Boyini
Page 98 of 142
How to use a single MySQL query to count column values ignoring null?
For this, you can COUNT() method, which does not include NULL value. Let us first create a table −mysql> create table DemoTable -> ( -> Name varchar(100), -> CountryName varchar(100) -> ); Query OK, 0 rows affected (0.49 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John', null); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Chris', 'US'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('Robert', null); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('Bob', 'UK'); Query ...
Read MoreImplement MySQL LIMIT and OFFSET in a single query stating its difference
The LIMIT tells about how many records you want while OFFSET gives the records from the given position+1. Let us first create a table −mysql> create table DemoTable -> ( -> Name varchar(100) -> ); Query OK, 0 rows affected (1.33 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.27 sec) mysql> insert into DemoTable values('David'); Query OK, 1 row affected (0.27 sec) mysql> insert into DemoTable values('Bob'); Query OK, 1 ...
Read MoreHow to use special characters in column names with MySQL?
Using backticks around the column name will allow you to use special characters. Let us first create a table −mysql> create table DemoTable -> ( -> `Student-Id` int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> `Student-Name` varchar(100), -> `Student-Age` int -> ); Query OK, 0 rows affected (0.55 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(`Student-Name`, `Student-Age`) values('Chris', 21); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable(`Student-Name`, `Student-Age`) values('Mike', 19); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable(`Student-Name`, `Student-Age`) values('Bob', 18); Query OK, ...
Read MoreCan we use semicolon as a MySQL DEMILITER?
No, we cannot. If you still did it, then stored procedure won’t get created. Therefore, first you need to change your DELIMITER from semicolon(;) to others like (// ,??..etc). Following is the syntax −DELIMITER // CREATE PROCEDURE yourProcedureName() BEGIN yourStatement1, . . . . N END // DELIMITER ;Let us implement the above syntax in order to create a stored procedure −mysql> DELIMITER // mysql> CREATE PROCEDURE get_Message() -> BEGIN -> SELECT CONCAT("HELLO", " ", "MYSQL USERS"); -> END -> // Query OK, 0 rows affected (0.23 sec) mysql> DELIMITER ;Now you can call the stored ...
Read MoreCan we use PRIMARY KEY( column1, column2) in MySQL to make pairs?
Yes, you can use below syntax. Following is the syntax −PRIMARY KEY(yourColumnName1, yourColumnName2);Let us first create a table −mysql> create table DemoTable -> ( -> StudentFirstName varchar(100), -> StudentLastName varchar(100), -> StudentAge int, -> StudentCountryName varchar(100), -> PRIMARY KEY(StudentFirstName, StudentLastName) -> ); Query OK, 0 rows affected (0.74 sec)Let us check the description of the table −mysql> desc DemoTable;OutputThis will produce the following output −+--------------------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------------------+--------------+------+-----+---------+-------+ | StudentFirstName | ...
Read MoreImplement multiple COUNT() in a single MySQL query
For this, use CASE statement. Let us first create a table −mysql> create table DemoTable -> ( -> LastName varchar(100) -> ); Query OK, 0 rows affected (0.60 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Smith'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Brown'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Brown'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Smith'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('Taylor'); Query OK, 1 ...
Read MoreHow to add multiple intervals to DATE_ADD() in MySQL?
The current date and time is as follows −mysql> select now();OutputThis will produce the following output −+---------------------+ | now() | +---------------------+ | 2019-06-15 12:24:06 | +---------------------+ 1 row in set (0.00 sec)Let us first create a table −mysql> create table DemoTable ->( -> ArrivalDate datetime -> ); Query OK, 0 rows affected (1.15 sec)Insert some records in the table using insert command. Here, we are adding multiple intervals to the DATE_ADD() method −mysql> insert into DemoTable values(DATE_ADD(DATE_ADD(NOW(), INTERVAL 6 MONTH), INTERVAL 1 YEAR)); Query OK, 1 row affected (0.13 sec) ...
Read MoreHow to remove border in navigationBar in swift?
To remove the border from a navigation bar in swift, we just need to add a few lines of code. Let’s see how the navigation bar looks when we run it without changing anything.Now let’s try to hide the line/ border shown in the above result.The navigation bar has two things that give it the default view of a grey shadow along with bottom line as shown above. One is the background image, and the other is the shadow image.First, we’ll hide the shadow image, by setting it to empty image and see how it looks.In your viewDidLoad add the ...
Read MoreHow to use UICollectionView in Swift?
To use collection view in swift, first, we need to create a collection View. We can either drag and drop it to the storyboard, or we can make it programmatically. After that, we need to confirm our class to UICollectionViewDataSource and UICollectionViewDelegate. Also if we need custom cell size and layouts, we need to confirm it to UICollectionViewDelegateFlowLayout.Let’s see the step required to create a collection View programmatically.func initCollection() { let layout = UICollectionViewFlowLayout() layout.itemSize = CGSize(width: 50, height: 50) let collection = UICollectionView.init(frame: self.view.frame, collectionViewLayout: layout) collection.dataSource = self collection.delegate = self collection.backgroundColor ...
Read MoreHow to create a Custom Dialog box on iOS App using Swift?
To create a dialog box in swift we’ll make use of UIAlertController which is an important part of UIKit. We’ll do this with help of an iOS application and a sample project.First of all, we’ll create an empty project, then inside its default view controller, we’ll perform the following operations.We’ll create an UIAlertController object.let alert = UIAlertController.init(title: title, message: description, preferredStyle: .alert)We’ll create an actionlet okAction = UIAlertAction.init(title: "Ok", style: .default) { _ in print("You tapped ok") //custom action here. }We’ll add the action to the alert and present italert.addAction(okAction) self.present(alert, animated: true, completion: nil)Now we’ll convert this ...
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