Managed C++/CLI

13-Mar-07 3:52

Hi All,

I am writing code snippet that insert records into a table which has a primary key on 2 columns..say for example Column X and Column Y..

I want to prevent duplication of records from being inserted into the table using C++..is there any way i can acheive this..i dont want to use Maps for storing the already inserted combination and thereby comparing before insertion..is there any other way to acheive this..

Thanks In Advance

led mike13-Mar-07 5:20

led mike

13-Mar-07 5:20

Subramaniam s.V. wrote:
is there any other way to acheive this..

You mean like using the database? Yes there is.

led mike

Subramaniam s.V.13-Mar-07 5:27

13-Mar-07 5:27

Can you tell me how we go about doing it?

led mike13-Mar-07 5:47

led mike

13-Mar-07 5:47

The obvious brute force way is to query the database for the key, however most modern databases allow you to put a unique constraint on the key which will cause the insert to fail. If you are interested in using a database solution ( I recommend it), try asking a question in the SQL forum here on CodeProject.

led mike

Subramaniam s.V.13-Mar-07 5:53

13-Mar-07 5:53

yeah thats right Led.

Ultimate solution would be to handle it in the database level. I completely agree with you on this point. Infact, my database by default handles this duplication. The problem is, my requirement is that, i need to insert records into a table by traversing up a Tree hierarchy and in my requirement there is a bright chance that duplicate records can be inserted into the database. when i try to insert a duplicate record it throws an error and comes out. All that I want is, if there is duplcaition, I want to skip that insertion from happening and proceed with further insertion of other records

hope you got the problem now..if not let me know i ll explain you the scenario in detail

Subramaniam s.V.13-Mar-07 5:30

13-Mar-07 5:30

In the sense, is there any other way to handle this using C++ itself?

without using any other datastructure to store the information about already inserted records, is there a way to handle duplication?

Link List in C++.NET

Software_Specialist13-Mar-07 1:14

Software_Specialist

13-Mar-07 1:14

Hi all,
I am starting with a contact manager application. And for this i need to have a double link list to get the data from the csv file.
So that i can add new contact, delete contacts, update contact and save contact.
Is linklist and node class already there in C++.NET
or do i have to create one.
And one more thing i would like to ask is do i have to sort the list before i can read it (using doubly linked list). I mean do i have to write a sort function. Which sort method would be best for this application ?
Thanks a lot

Maximilien13-Mar-07 3:12

Maximilien

13-Mar-07 3:12

Why use such an antiquated structure ? simply use STL lists ( or vector ) or some .net collection classes.

Software_Specialist wrote:
I mean do i have to write a sort function.

yes, or minimally, depending on your data structure, a compare function ( can be used to sort ) when inserting.

Software_Specialist wrote:
Which sort method would be best for this application ?

The quicksort, or use the one that is used when sorting with the data structure you are using.

Maximilien Lincourt
Your Head A Splode - Strong Bad

Software_Specialist13-Mar-07 3:35

Software_Specialist

13-Mar-07 3:35

Maximilien wrote:
Why use such an antiquated structure ? simply use STL lists ( or vector ) or some .net collection classes.

What do you mean by this. Well i am bit new in C++.Net(windows programming).
So by STL lists or .net collection classes we can perform the doubly linked list functionality or what ?
Is there any good link to learn all this..

Thanks for your reply

Maximilien13-Mar-07 4:05

Maximilien

13-Mar-07 4:05

IMO, there are no valid reasons in 2007 to use a double linked list.

STL and .net collection classes hide the internal technicality, you only need to concentrate on the functionality of your task at hand; you don't need to know how the std::list or the System.Collections.SortedList are implemented.

Maximilien Lincourt
Your Head A Splode - Strong Bad

Dmitry Khudorozhkov13-Mar-07 6:33

Dmitry Khudorozhkov

13-Mar-07 6:33

Maximilien wrote:
IMO, there are no valid reasons in 2007 to use a double linked list.

There is a reason to use a double linked list in 2007.

There is no need to reinvent the wheel by coding the double linked list by hand Wink | ;)

-------------------------
Don't worry, be happy Blush | :O

)

led mike13-Mar-07 5:18

led mike

13-Mar-07 5:18

Software_Specialist wrote:
I am starting with a contact manager application. And for this i need to have a double link list to get the data from the csv file.

Sounds like an appropriate application for a database.

led mike

George L. Jackson13-Mar-07 7:39

George L. Jackson

13-Mar-07 7:39

In the System::Collections::Generic namespace, there is a doubly linked list called LinkList. However, as far as I know, you have to write your own sort.

"We make a living by what we get, we make a life by what we give." --Winston Churchill

have a question for a hw assiment, don't know how to do it?

George L. Jackson13-Mar-07 7:58

George L. Jackson

13-Mar-07 7:58

You might want to consider looking at the C5 Generic Collection Library:

http://www.itu.dk/research/c5/[^]

"We make a living by what we get, we make a life by what we give." --Winston Churchill

bigtimer102212-Mar-07 17:38

bigtimer1022

12-Mar-07 17:38

3. Write a program which outputs frequency of digits in a given integer. For example, if the number is 12424329, output will be
Number Frequency
1 (space) 1
2 (space) 3
3 (space) 1
4 (space) 2
9 (space) 1

Use a switch statement to obtain frequency of the digits.

This means nothing (space) i just put in so the numbers would line up

Re: have a question for a hw assiment, don't know how to do it?

User 58385212-Mar-07 19:09

User 583852

12-Mar-07 19:09

Big Timer? Big timers dont need help with their home work. Big timers dont cross post to multiple forums. Big timers dont post things to unrelated forums. More than anything, big timers dont call themselves big timers

How much are you willing to pay to have your homework done for you?

System.IO.Path.IsPathRooted() does not behave as I would expect

Re: have a question for a hw assiment, don't know how to do it?

bigtimer102212-Mar-07 19:18

bigtimer1022

12-Mar-07 19:18

well its due tomorrow and i don't know how to do it so...

Re: have a question for a hw assiment, don't know how to do it?

User 58385212-Mar-07 19:22

User 583852

12-Mar-07 19:22

bigtimer1022 wrote:
well its due tomorrow and i don't know how to do it so...

...so why did you leave it till now?

System.IO.Path.IsPathRooted() does not behave as I would expect

Re: have a question for a hw assiment, don't know how to do it?

Christian Graus14-Mar-07 9:30

Christian Graus

14-Mar-07 9:30

By the time I saw this, you had failed your assignment. One would hope that you learned from this to do your own work, instead of drinking and posting the question online at the last minute. If you do try to do your own homework in future, you'll find we'd love to help if you get stuck. Just not when you post a (trivial) question and show no sign of having made any attempt to solve it.

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

dynamic pictureBox creation

sarah_malik12-Mar-07 9:08

sarah_malik

12-Mar-07 9:08

Hi all,

I have a form that contains one button and one textbox, the textbox will take a number that will be passed to another form. I have done this successfully.
The thing is that I need the second form to create a number of pictureboxes = the number received from the first form.

Any ideas?

Jeff J Anderson12-Mar-07 9:18

Jeff J Anderson

12-Mar-07 9:18

call:

gcnew PictureBox()

for each. Then set the Image and other properties as desired.

sarah_malik12-Mar-07 9:57

sarah_malik

12-Mar-07 9:57

Hi kilroytrout,

I have done this in the Form_load as follows:

<br />
pictureBoxX = gcnew System::Windows::Forms::PictureBox();<br />
pictureBoxX->Location = System::Drawing::Point(24, 262);<br />
pictureBoxX->Name = L"pictureBoxX";<br />
pictureBoxX->Size = System::Drawing::Size(45, 49);<br />
pictureBoxX->SizeMode = System::Windows::Forms::PictureBoxSizeMode::Zoom;<br />
pictureBoxX->Image = Drawing::Image::FromFile("avg.jpg");

but nothing appears in the form Confused | :confused:

Jeff J Anderson12-Mar-07 11:29

Jeff J Anderson

12-Mar-07 11:29

Did you add each PictureBox to the form's control collection?

form->Controls->Add(pictureBoxX);