Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Articles by Sreemaha
Page 4 of 6
What is the difference between method hiding and method overriding in Java?
When super class and the sub class contains same instance methods including parameters, when called, the super class method is overridden by the method of the sub class. WIn this example super class and sub class have methods with same signature (method name and parameters) and when we try to invoke this method from the sub class the sub class method overrides the method in super class and gets executed. Example class Super{ public void sample(){ System.out.println("Method of the Super class"); } } public class MethodOverriding extends ...
Read MoreHow do I write variable names in Java?
While choosing an identifier to declare a variable in Java you need to keep the following points in mind. The name of the variable should begin with either alphabet or, an underscore (_) or, a dollar ($) sign. The identifiers used for variables must not be keywords. No spaces or special characters are allowed in the variable names of Java. Variable names may contain 0 to 9 numbers (if not at the beginning). Variable names are case sensitive i.e. MY_NUM is different from my_num. If you use two words in a identifier then the you should follow camel case ...
Read MoreHow can I get the records from MySQL table in result set in a particular way?
For getting the records from MySQL table in the result set in a particular way either ascending or descending, we need to use the ORDER BY clause along with ASC or DESC keywords. If we will not use any of the above-mentioned keywords then MySQL by default return the records in ascending order. The ORDER BY clause returned the result set based on a particular field (ascending or descending order) with which we will use the ORDER BY clause. Suppose we want to sort the rows of the following table −mysql> Select * from Student; +--------+--------+--------+ | Name | ...
Read MoreHow can we perform START transactions inside MySQL stored procedure?
As we know the START transaction will start the transaction and set the auto-commit mode to off. In the following example, we have created a stored procedure with a START transaction which will insert a new record in table employee.tbl having the following data −mysql> Select * from employee.tbl; +----+---------+ | Id | Name | +----+---------+ | 1 | Mohan | | 2 | Gaurav | | 3 | Rahul | +----+---------+ 3 rows in set (0.00 sec)Examplemysql> Delimiter // mysql> Create Procedure st_transaction() -> BEGIN -> START TRANSACTION; -> INSERT INTO employee.tbl(name) values ...
Read MoreHow can we see the list of stored procedures and stored functions in a particular MySQL database?
We can see the list of the stored procedure and stored functions in a particular database by using the following query on INFORMATION_SCHEMA.ROUTINES as follows −mysql> SELECT ROUTINE_TYPE, ROUTINE_NAME FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_SCHEMA = 'query'; +--------------+--------------+ | ROUTINE_TYPE | ROUTINE_NAME | +--------------+--------------+ | PROCEDURE | allrecords | | FUNCTION | Hello | +--------------+--------------+ 2 rows in set (0.04 sec)The above query returns the procedure named ‘allrecords’, and function named ‘Hello’ which are stored in the database named ‘query’.
Read MoreHow can we get only the name having no other details about the tables in MySQL database?
With the help of SHOW TABLES command, we can get only the name having no other information about the tables. For example, we can see the list of tables in a database named tutorial as follows −mysql> show tables; +--------------------+ | Tables_in_tutorial | +--------------------+ | student | +--------------------+ 1 row in set (0.00 sec)
Read MoreHow can I restore a file created by mysqldump?
Suppose if we want to restore a file that has been created by mysqldump then we can restore in an existing database or in a new database after creating it. Then with the help of SOURCE statement, we can restore it. We can illustrate it by an example:ExampleIn this example, we are restoring the table named student_info.sql which has been dumped. It was basically in the database name ‘query’. Now we will restore it into a database named ‘tutorials’.mysql> Use Tutorials; Database changed mysql> SOURCE student_info.sql; Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected ...
Read MoreWhat is the difference between YEAR(2) and YEAR(4) in MySQL?
YEAR(2) stores a year in 2-digit format. For example, we can write 69 to store 1969 a year. In YEAR (2), the year can be specified from 1970 to 2069 (70 to 69).YEAR(4) stores a year in 4-digit format. For example, we need to write 19669 to store 1969 as a year. In YEAR (4), the year can be specified from 1901 to 2155.MySQL interprets 2-digit year values with the assistance of following rules:Year values within the vary 00-69 are converted to 2000-2069.Year values in the range 70-99 are converted to 1970-1999.We must not store date values as a 2-digit ...
Read MoreWhy is char[] preferred over String for storing passwords?
Yes, Storing password in String object is not safe for following reasons −String objects are immutable and until garbage collected, they remain in memory.String being plain text can be tracked in memory dump of the application.In log, String based password may be printed which can cause a problem.Char[] can be cleared or wiped out after the job is done.
Read MoreThe most elegant ways to iterate the words of a java string.
Just split the string based on space and then iterate it. See the example below −Examplepublic class Tester { public static void main(String[] args) { String test = "I love learning Java"; String[] subStrings = test.split(" "); for(String subString: subStrings) { System.out.println(subString); } } }OutputI love learning Java
Read More