Questions tagged [derived]
429 questions
-1
votes
2 answers
why my derived class is an abstract class? C++
//abstract product
class AbstractProduct
{
public:
virtual void diplay(void) = 0;
};
//concrete product
class Histogram : public AbstractProduct
{
public:
Histogram()
{
cout << "default construct a Histogram!" << endl;
}
…
user4185295
- 17
- 1
- 1
-1
votes
1 answer
MySQL: Order of derived table is forgotten
Sometime between yesterday and this June my hosting provider must have updated their MySQL since the following query now yields a different result than before.
I use the query as part of a union, but I have only copy/pasted the none working part -…
Peach2tm
- 13
- 2
-1
votes
1 answer
Mongo : How to query particular derived class in mongo?(using monogcsharpdriver 1.9.2)
public class Person
{
List Contacts {get;set;}
}
public abstract class Contact
{
string Value {get;set;}
}
public class Email : Contact
{
}
public class Chat: Contact
{
}
I have typed collection for Person.
How can I query…
dspatil
- 327
- 2
- 8
-1
votes
1 answer
EntityFramework code-first ignoring derived columns when creating database
I would like some of tables in my database to have standard columns such as createdBy, ModifiedBy, CreatedDateTime, modifiedDateTime etc.
So, I created an interface with those properties and implemented the interface in an abstract base class. I…
RT.
- 435
- 2
- 9
- 25
-1
votes
1 answer
Derived Column Functionality error
I have 2 new columns from Derived Column functionality and I have to merge them both into one Column and feed it to the destination Table.
Derived column 1:
ABC
BBC
CBC
Derived Column 2:
HPC
DRT
RTY
Derived Column 3 should…
user2917483
- 13
- 2
-1
votes
2 answers
c++ Inheritance class constructor
I have a slight problem where to be honest I am totally confused with derived class constructors and need some help.
I have a base class with the parameterised constructor:
Element::Element(RandomNumber &rnd, Console &console)
: rnd(rnd),…
Alyn
- 55
- 1
- 7
-1
votes
2 answers
two classes within a class
What is a better way to implement this in C++ (without if-else). In C I can initialize function pointer, and then just call function pointers. So if you look at class C, some objects of class C use only class A and some class B. I am more familiar…
user1869474
- 57
- 1
- 1
- 6
-1
votes
2 answers
Friend of a derived class can access what variables?
To simplify my problem, I have something like this:
class Base {
private:
protected:
int a,b;
string c;
public:
[some functions here]
}
class Derived : public Base{
[some variables and functions]
friend void…
user1799323
- 649
- 8
- 25
-1
votes
1 answer
SQL Automatic Derived field
Ok, I'm looking for a way to make a certain field be equal to the sum of 3 other fields. I have 3 different rating fields, and then an 'overall rating' field, which I need to be automatically equal the sum of the other 3. I know how to retrieve the…
cameronjonesweb
- 2,435
- 3
- 25
- 37
-1
votes
2 answers
Cannot create Member Object if it's part of a parent class
I tried to create a member object (hope this terminus is correct) and it worked. But if I derive the class of the object it fails. Why is this the case and how do I solve that problem?
class test
{
protected:
int id;
public:
…
womdom
- 55
- 1
- 6
-2
votes
1 answer
SQL derived value by a set of Row
Hi my table looks like this
Combination of Rows with same S id is termed as a family.
Output should have a Calculated Tier code based on below derivation
Output put should be
Output
First time i am using Stackoverflow. I need a query in db2 and I…
Lovely Kolli
- 1
- 1
-2
votes
2 answers
C++ Segmentation fault when trying to insert derived objects into an Object Array
I'm doing a project where we need to create a basic Zoo Tycoon game, in which we create a base class called Animal, 3 derived classes of Animal: Tiger, Penguin, Turtle. We also need to create a Zoo class that holds 3 separate arrays for each animal.…
Arjun Kahlon
- 1
- 1
-2
votes
2 answers
New method cannot be accessed by new object
Who ya gonna call?
Unrelated code to pose the problem. Not the best editor tool so being terse. Thanks.
A new method that is part of the derived class cannot be accessed by the new
object. All the Intellisense sees are the abstract parts of the…
Elliot
- 101
-2
votes
2 answers
Segmentation fault when calling derived class method
I have a problem related to designing derived classes with array parameters. I have class B derived from A. And class BB derived from AA with array of B and A respectively...
#include
class A
{
public:
A(){}
virtual void…
user3147006
- 27
- 4
-2
votes
1 answer
C++ Error when I call a parent method as a derived object
#include
#include
using namespace std;
class parent
{
int x=0;
public:
int getx()
{
return x;
}
};
class child : public parent
{
int x=7;
};
int main()
{
parent cat;
cout << cat.getx();
…
dfries
- 1
- 1