What is used for storage

[Marcel]

Hello all,

I am a C++ beginner.

I would like to know where and how a C++ application stores it's data.

For example, imagine an application to manage your DVD collection. DVD can
be enterd into it by typing a name, duration, description. What is most
common, best practice: to store the DVD's entrys in a flatfile, in a
database (what database) or is there another solution.

I can imagine that maybe for not much data a flatfile is the best solution
but as the DVD collection will grow over time maybe a database is a better
solution?

Marcel

[Ben Pope]

Marcel wrote:

Hello all,

I am a C++ beginner.

I would like to know where and how a C++ application stores it's data.
Where you tell it to.
For example, imagine an application to manage your DVD collection. DVD can
be enterd into it by typing a name, duration, description. What is most
common, best practice: to store the DVD's entrys in a flatfile, in a
database (what database) or is there another solution.
Well, RAM, initially, and then if you need it to persist, then a file
and a database or probably two most common options.
I can imagine that maybe for not much data a flatfile is the best solution
but as the DVD collection will grow over time maybe a database is a better
solution?

Correct.

For now, I suggest you use a file. When performance becomes a problem,
work out another solution.

If you abstract the reading and writing behind an interface, then you
should be able to change the implementation from a file to a database
without changing too much code.

#include <vector>
#include <string>

class myData {};

// Pure abstract Interface
class serialiser {
public:
virtual ~serialiser() = 0 {}

virtual std::vector<myD ata> read() = 0 {}
virtual bool write(const std::vector<myD ata>& vec) = 0 {}
};

class file : public serialiser {
public:
file(std::strin g& filename) {/*open file*/}
~file() {/*close file*/}
std::vector<myD ata> read() { return std::vector<myD ata>(); }
bool write(const std::vector<myD ata>& vec) { return false; }
};
class database : public serialiser {};

int main() {
std::string filename("filen ame");
std::auto_ptr<s erialiser> dataStore(new file(filename)) ;
std::vector<myD ata> data = dataStore->read();
}

That should give you the basic idea, obviously all the difficult bits
are missing.

Ben Pope
--
I'm not just a number. To many, I'm known as a string...

[Stephan Brönnimann]

As you are a C++ beginner you should go for flat files first.
The disadvantage is that it can be accessed from the local machine only
(unless you're using shared file systems (NFS, Samba, ...)).
The design should encapsulate the I/O of an entry in the collection:
define the necessary interface in an abstract base class and provide
a concrete implementation that works with flat files.

Later you can expand your design by the strategy pattern and provide
an I/O interface to a database.

Regards, Stephan

[Marcel]

"Marcel" <so************ ***@nospam.com> schreef in bericht
news:fc******** *************** ***@cache40.mul tikabel.net...

Hello all,

I am a C++ beginner.

I would like to know where and how a C++ application stores it's data.

For example, imagine an application to manage your DVD collection. DVD can
be enterd into it by typing a name, duration, description. What is most
common, best practice: to store the DVD's entrys in a flatfile, in a
database (what database) or is there another solution.

I can imagine that maybe for not much data a flatfile is the best solution
but as the DVD collection will grow over time maybe a database is a better
solution?

Marcel

Ok thanks for your advice friends!

Marcel

[JustBoo]

On Wed, 11 Jan 2006 12:21:22 +0100, "Marcel"
<so************ ***@nospam.com> wrote:

Ok thanks for your advice friends!

Three small posts in an ocean of indifference.

Need I say more? No, no more. I will try to do my part as well.

[In a quiet humble voice]
"No crime is so great as daring to excel."
- Winston Churchill

[Howard]

"JustBoo" <Ju*****@BooWho .com> wrote in message
news:tp******** *************** *********@4ax.c om...

On Wed, 11 Jan 2006 12:21:22 +0100, "Marcel"
<so************ ***@nospam.com> wrote:

Ok thanks for your advice friends!

Three small posts in an ocean of indifference.

Need I say more? No, no more. I will try to do my part as well.

[In a quiet humble voice]
"No crime is so great as daring to excel."
- Winston Churchill

What????? Perhaps you wanted alt.poetry?

-Howard

[Default User]

Ben Pope wrote:

Marcel wrote:

Hello all,

I am a C++ beginner.

I would like to know where and how a C++ application stores it's
data.

Where you tell it to.

For example, imagine an application to manage your DVD collection.
DVD can be enterd into it by typing a name, duration, description.
What is most common, best practice: to store the DVD's entrys in a
flatfile, in a database (what database) or is there another
solution.

Well, RAM, initially, and then if you need it to persist, then a file
and a database or probably two most common options.

I can imagine that maybe for not much data a flatfile is the best
solution but as the DVD collection will grow over time maybe a
database is a better solution?

Correct.

Depends. The size doesn't matter all that much, especially with modern
computers. You can rip through even a sizeable flatfile in short order.
It's really more of how you're using the data. If there are going to be
lots of complicated searches and such, then a relational database will
become important. Naturally, proper design of the tables becomes vital
at that point, but that's well outside the scope of this newsgroup.

Brian

[JustBoo]

On Wed, 11 Jan 2006 17:49:32 GMT, "Howard" <al*****@hotmai l.com>
wrote:

"JustBoo" <Ju*****@BooWho .com> wrote in message
news:tp******* *************** **********@4ax. com...

On Wed, 11 Jan 2006 12:21:22 +0100, "Marcel"
<so************ ***@nospam.com> wrote:
[In a quiet humble voice]
"No crime is so great as daring to excel."
- Winston Churchill

What????? Perhaps you wanted alt.poetry?
-Howard

Don't quit your day job Howie. If you have one....

Men occasionally stumble over the truth, but most
of them pick themselves up and hurry off as if
nothing had happened. - Winston Churchill

[red floyd]

JustBoo wrote:

[insult redacted]

*PLONK*

[Howard]

"JustBoo" <Ju*****@BooWho .com> wrote in message
news:rf******** *************** *********@4ax.c om...

On Wed, 11 Jan 2006 17:49:32 GMT, "Howard" <al*****@hotmai l.com>
wrote:

"JustBoo" <Ju*****@BooWho .com> wrote in message
news:tp****** *************** ***********@4ax .com...

On Wed, 11 Jan 2006 12:21:22 +0100, "Marcel"
<so************ ***@nospam.com> wrote:
[In a quiet humble voice]
"No crime is so great as daring to excel."
- Winston Churchill

What????? Perhaps you wanted alt.poetry?
-Howard

Don't quit your day job Howie. If you have one....

Men occasionally stumble over the truth, but most
of them pick themselves up and hurry off as if
nothing had happened. - Winston Churchill

Ooh, it called me "Howie"! A touch, I do confess it! I fear I breathe my
last. Oh woe...

*plonk*