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George John has Published 1081 Articles

George John
1K+ Views
There are lots of options available to replace NULL values using select statement. You can use CASE statement or IFNULL() or COALESCE()Case 1 − Using IFNULL()The syntax of IFNULL() is as follows −SELECT IFNULL(yourColumnName, ’yourValue’) AS anyVariableName from yourTableName;Case 2 − Using COALESCE()The syntax of COALESCE() is as follows −SELECT ... Read More

George John
3K+ Views
To change the root username in MySQL, you need to use UPDATE and SET command. The syntax is as follows −UPDATE user set user = ’yourNewUserName’ WHERE user = ’root’;To understand the above syntax, let us switch the database to MySQL using USE command.The query is as follows to switch ... Read More

George John
2K+ Views
You can use NULLIF() from MySQL to replace 0 with NULL. The syntax is as follows −SELECT *, NULLIF(yourColumnName, 0) as anyVariableName from yourTableName;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table Replace0WithNULLDemo -> ( ... Read More

George John
485 Views
To select a single row in MySQL, you can use LIMIT. At first, let us create a table. The query to create a table is as follows −mysql> create table selectWithPrimaryKey -> ( -> Id int NOT NULL AUTO_INCREMENT, -> Name varchar(20), -> Age int, ... Read More

George John
6K+ Views
To MySQL order string with numbers, the following is the syntax, wherein we have used ORDER BY, SUBSTR() and CAST() −SELECT *FROM yourTableName ORDER BY SUBSTR(yourColumnName FROM 1 FOR 2), CAST(SUBSTR(yourColumnName FROM 2) AS UNSIGNED);To understand the above syntax, let us create a table. The query to create a table ... Read More

George John
2K+ Views
You can use GROUP BY command for select with distinct id. The syntax is as follows −SELECT *FROM yourTableName GROUP BY yourColumnName;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table DistinctIdDemo -> ( -> Id ... Read More

George John
4K+ Views
To select distinct combinations from two columns, you can use CASE statement. Let us create a table with some columns.The query to create a table is as follows −mysql> create table select_DistinctTwoColumns -> ( -> Id int NOT NULL AUTO_INCREMENT, -> FirstValue char(1), -> SecondValue char(1), ... Read More

George John
19K+ Views
You can use ORDER BY RIGHT() function to order by last 3 chars in MySQL. The syntax is as follows −SELECT *FROM yourTableName ORDER BY RIGHT(yourColumnName, 3) yourSortingOrder;Just replace the ‘yourSortingOrder’ to ASC or DESC to set the ascending or descending order respectively.To understand the above syntax, let us create ... Read More

George John
5K+ Views
An intent filter is an instance of the IntentFilter class. Intent filters are helpful while using implicit intents, It is not going to handle in java code, we have to set it up in AndroidManifest.xml. Android must know what kind of intent it is launching so intent filters give the ... Read More

George John
4K+ Views
An Iterator can be used to loop through an ArrayList. The method hasNext( ) returns true if there are more elements in ArrayList and false otherwise. The method next( ) returns the next element in the ArrayList and throws the exception NoSuchElementException if there is no next element.A program that ... Read More