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MySQL REPLACE() function can replace all the occurrences of a substring with another substring within a string.SyntaxREPLACE(str, find_string, replace_with)Here Str is a string which have the substring.Find_string is a substring which is present one or more times within the strung str.Replace_with is a substring which will replace every time it finds find_string within str.Examplemysql> Select REPLACE('Ram, My Name is Ram', 'Ram', 'Shyam'); +------------------------------------------------+ | REPLACE('Ram, My Name is Ram', 'Ram', 'Shyam') | +------------------------------------------------+ | Shyam, My Name is Shyam | +------------------------------------------------+ 1 row in set (0.00 sec)
In this case, MySQL will not pad anything and truncate the characters from the original string up to the value of length provided as the argument in LPAD() or RPAD() functions.Examplemysql> Select LPAD('ABCD',3,'*'); +--------------------+ | LPAD('ABCD',3,'*') | +--------------------+ | ABC | +--------------------+ 1 row in set (0.00 sec) mysql> Select RPAD('ABCD',3,'*'); +--------------------+ | RPAD('ABCD',3,'*') | +--------------------+ | ABC | +--------------------+ 1 row in set (0.00 sec)We can observe from the above example that both the functions do not pad ‘*’ and truncate the original string up to the length specified i.e. 3 as the argument.
Suppose if we want to make the output of REPEAT() function more readable then we can use another function/s with it. For example, if we want to add space or some other character between the repeated values then we can use CONCAT() function.Examplemysql> Select REPEAT(CONCAT(' *', Subject, '* '), 3)AS Subject_repetition from student; +-----------------------------------------+ | Subject_repetition | +-----------------------------------------+ | *Computers* *Computers* *Computers* | | *History* *History* *History* | | *Commerce* *Commerce* *Commerce* | | *Computers* *Computers* *Computers* | ... Read More
For repeating the values stored in a data column of MySQL table, the name of the column must be passed as the first argument of REPEAT() function. The data from ‘Student’ table is used to demonstrate it:Examplemysql> Select REPEAT(Name,3)AS Name from student; +-----------------------+ | Name | +-----------------------+ | GauravGauravGaurav | | AaravAaravAarav | | HarshitHarshitHarshit | | GauravGauravGaurav | | YashrajYashrajYashraj | +-----------------------+ 5 rows in set (0.00 sec)
In Java, after swing components displayed on the screen, they can be operated by only one thread called Event Handling Thread. We can write our code in a separate block and can give this block reference to Event Handling thread. The SwingUtilities class has two important static methods, invokeAndWait() and invokeLater() to use to put references to blocks of code onto the event queue.Syntaxpublic static void invokeAndWait(Runnable doRun) throws InterruptedException, InvocationTargetException public static void invokeLater(Runnable doRun)The parameter doRun is a reference to an instance of Runnable interface. In this case, the Runnable interface will not be passed to the constructor of a Thread. The Runnable interface is simply ... Read More
MySQL returns NULL if the argument of QUOTE() function is NULL.Examplemysql> Select QUOTE(NULL); +-------------+ | QUOTE(NULL) | +-------------+ | NULL +-------------+ 1 row in set (0.00 sec) mysql> Select Name, QUOTE(NULL) from student where id = 1; +--------+-------------+ | Name | QUOTE(NULL) | +--------+-------------+ | Gaurav | NULL | +--------+-------------+ 1 row in set (0.08 sec)
If we want to copy tables or databases from one MySQL server to another, then use the mysqldump with database name and table name.Run the following command at the source host. This will dump the complete database into dump.txt file.$ mysqldump -u root -p database_name table_name > dump.txt password *****We can copy complete database without using a particular table name as explained above.Now, ftp dump.txt file on another host and use the following command. Before running this command, make sure we have created database_name on the destination server.$ mysql -u root -p database_name < dump.txt password *****Another way to accomplish this without ... Read More
JFrameThe components added to the frame are referred to as its contents, these are managed by the contentPane. To add a component to a JFrame, we must use its contentPane instead.A JFrame contains a window with title, border, (optional) menu bar and user-specified components.A JFrame can be moved, resized, iconified and it is not a subclass of JComponent.By default, JFrame is displayed in the upper-left corner of the screen. To display a frame at a specified location, we can use the setLocation(x, y) method in the JFrame class.Exampleimport java.awt.*; import java.awt.event.*; import javax.swing.*; public class JFrameDemo { public static void main(String s[]) { ... Read More
We have seen the MySQL SELECT command to fetch data from the MySQL table. We can also use a conditional clause called as the WHERE clause to select the required records.A WHERE clause with the ‘equal to’ sign (=) works fine where we want to do an exact match. Like if "tutorial_author = 'Sanjay'". But there may be a requirement where we want to filter out all the results where the tutorial_author name should contain "jay". This can be handled using MySQL LIKE operator along with the WHERE clause.If the MySQL LIKE operator is used without a wildcard character, the ... Read More
As we know that NOT LIKE operator is used along with WILDCARD characters for not getting the string having specified string. Basically, WILDCARD is the characters that help search data matching complex criteria. Followings are the types of wildcard which can be used in conjunction with NOT LIKE operator:% - The PercentageThe ‘%’ wildcard is used to specify a pattern of 0, 1 or more characters. A basic syntax for using % wildcard with NOT LIKE operator is as follows:Select Statement…Where column_name NOT LIKE ‘X%’Here X is any specified starting pattern such as the single character of more and % matches ... Read More