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Articles by Giri Raju
Page 6 of 7
inheritance(is-a) v/s composition (has-a) relationship in Java
IS-A RelationshipIS-A is a way of saying − This object is a type of that object. Let us see how the extends keyword is used to achieve inheritance. public class Animal { } public class Mammal extends Animal { } public class Reptile extends Animal { } public class Dog extends Mammal { }Now, if we consider the IS-A relationship, we can say −Mammal IS-A AnimalReptile IS-A AnimalDog IS-A MammalHence: Dog IS-A Animal as wellWith the use of the extends keyword, the subclasses will be able to inherit all the properties of the superclass except for the private properties of the ...
Read MoreDifference between SBObob GetItemPrice and CompanyService GetItemPrice in SAP B1?
As per my understanding, SBObob takes fewer parameters but provide the more accurate result for item price taking into accounts for BP and quantity of items, etc. CompanyService GetItemPrice accepts more parameters however information is scarce in the SDK help file for this method. Also, note that there is no information on this return type.ItemPriceReturnParams uses below properties:CurrencyDiscountPrice
Read MorePass by reference vs Pass by Value in java
Call by Value means calling a method with a parameter as value. Through this, the argument value is passed to the parameter. While Call by Reference means calling a method with a parameter as a reference. Through this, the argument reference is passed to the parameter. In call by value, the modification done to the parameter passed does not reflect in the caller's scope while in the call by reference, the modification done to the parameter passed are persistent and changes are reflected in the caller's scope. But Java uses only call by value. It creates a copy of references ...
Read MoreHow to create a dynamic 2D array in Java?
If you wish to create a dynamic 2d array in Java without using List. And only create a dynamic 2d array in Java with normal array then click the below linkYou can achieve the same using List. See the below program. You can have any number of rows or columns.Exampleimport java.util.ArrayList; import java.util.List; public class Tester { public static void main(String[] args) { List rows = new ArrayList(); rows.add(new int[]{1, 2, 3}); rows.add(new int[]{1, 2}); ...
Read Morejava access modifiers with method overriding
Yes, an overridden method can have a different access modifier but it cannot lower the access scope.The following rules for inherited methods are enforced -Methods declared public in a superclass also must be public in all subclasses.Methods declared protected in a superclass must either be protected or public in subclasses; they cannot be private.Methods declared private are not inherited at all, so there is no rule for them.
Read MoreHow can I change the default sort order of MySQL tables?
As we know that when we use ORDER BY Clause, the default sort order of MySQL table is ascending, start with the smallest value. We can change this default order by using DESC keyword along with ORDER BY Clause. The following example will clarify this concept −>mysql> Select * from STUDENT ORDER BY Name DESC; +--------+--------+--------+ | Name | RollNo | Grade | +--------+--------+--------+ | Gaurav | 100 | B.tech | | Aryan | 165 | M.tech | | Aarav | 150 | M.SC | +--------+--------+--------+ 3 rows in set (0.00 sec)We can see that after using the keyword DESC the default order has been changed from ascending to descending.
Read MoreHow to write a MySQL stored function that inserts values in a table?
As we know that function is best used when we want to return a result. Hence, when we will create stored functions for manipulating tables like to Insert or Update values then it would be more or less like stored procedures.ExampleIn the following example we are creating a stored function named ‘tbl_insert’ which will insert the values in a table named ‘student_marks’.mysql> Create Function tbl_insert(S_name Varchar(50), M1 INT, M2 INT, M3 INT, M4 INT) -> RETURNS INT -> DETERMINISTIC -> BEGIN -> INSERT INTO student_marks values(S_name, M1, M2, M3, M4); ...
Read MoreHow can I restore a database dumped by mysqldump?
Suppose if we have dumped the whole database and now want to restore it then we can do it with the following example −C:\mysql\bin>mysql -u root query < tutorials.sqlWith the help of above query, we are restoring the dumped database named ‘tutorials’, in the file tutorials.sql, into other database named ‘query’. It means that the tables of database ‘tutorials’ would be restored in a database named ‘query’.
Read MoreHow can we use the MySQL reserved words as an identifier?
We must have to use quotes with reserved words to use them as an identifier. The quotes can be single or double depends upon ANSI_QUOTES SQL mode.If this mode is disabled then the identifier quote character is the backtick (“`”). Consider the following example in which we created a table named ‘select’ −mysql> create table `select`(id int); Query OK, 0 rows affected (0.19 sec)If this mode is enabled then we can use backtick (“`”) and double quotes (“”) both as identifier quote character. Consider the following example in which we created a table named ‘trigger’ −mysql> Create table "trigger" (id ...
Read MoreWhat MySQL returns on passing an invalid string as an argument to STR_TO_DATE() function?
If we pass an invalid string as an argument to STR_TO_DATE() function then MySQL will return NULL as output along with a warning. Following is an example to understand the same −mysql> Select STR_TO_DATE('20173210', '%Y%d%m'); +-----------------------------------+ | STR_TO_DATE('20173210', '%Y%d%m') | +-----------------------------------+ | NULL | +-----------------------------------+ 1 row in set, 1 warning (0.00 sec)In the query above the string value is invalid because of wrong (32) day value. Hence it returns NULL values and a warning which is given below.mysql> Show warnings\G *************************** 1. row *************************** ...
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