Re: Fwd: [PHP] Storing indefinite arrays in database

2011-05-11 Thread Benedikt Voigt

Bastien,
thanks for the answer.
But as I understand the problem and your suggestion, this won’t work, or you 
have to explain it to me with this example.
For example, let’s reduce the function to two input fields and the following 
functioning:
InputField1=A InputField2=B OutputField=X
InputField1=A InputField2=C OutputField=Y
How can you store this in the form you suggested in a relational database?
Or would a non-relational database (e.g. an OO-database) make more sense?
Thanks,
Ben 


-Ursprüngliche Nachricht-
Von: Bastien Koert phps...@gmail.com
Gesendet: 10.05.2011 22:38:24
An: PHP General list php-general@lists.php.net
Betreff: Fwd: [PHP] Storing indefinite arrays in database

-- Forwarded message --
From: Bastien Koert phps...@gmail.com
Date: Tue, May 10, 2011 at 4:37 PM
Subject: Re: [PHP] Storing indefinite arrays in database
To: Benedikt Voigt benedikt.vo...@web.de


On Tue, May 10, 2011 at 4:16 PM, Benedikt Voigt benedikt.vo...@web.de wrote:
 Hi,
 I'am very new to PHP, so please any comment is welcome.

 I want to write a function in PHP, which takes X arguments and outputs a
 value.
 The functioning of this function should be stored in a db (mydb? or better
 alternatives?)
 The function would look up the result in the db based on the X arguments.

 But how can I store X arguments and the corresponding output value?
 If I limit the X arguments to a specific number like N=10, then I could
 create N=10 +1 columns in a table.
 But how should I do it if I don't want to limit myself to a fix number?

 Thanks for any comment!
 Ben

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My bad, copied only the OP not the list.


Create the DB to run in a vertical format

consider the horizontal style

record_id       field1   field2   field3   fieldN


which is great for fixed designs


The vertical format would be

record_id     attribute      argument




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Re: [PHP] Re: Storing indefinite arrays in database

2011-05-11 Thread Benedikt Voigt

Thanks Shawn,

yes, your second idea works for me. The first one not, as I need to 
search and join on it.

To continue your second idea with your example:

Arguments:
id  results_id  variablevalue
1   1   1   800
2   1   2   999
3   1   3   3.14

Results:
id  result
1   50
2   99

The Arguments and Results table would be filled dynamically by user content.
In order to run a function, I have to do N times a join, whereas N is the 
number of arguments:

select result
from Results join Arguments as A1 join Arguments as A2 join Arguments as A3
on Results.id=A1.results_id and
on Results.id=A2.results_id and
on Results.id=A3.results_id and
where
A1.variable=1 and A1.value=800 and
A2.variable=2 and A2.value=999 and
A3.variable=3 and A3.value=3.14 and
A1.results_id=Results.results_id and
A2.results_id=Results.results_id and
A3.results_id=Results.results_id

Theoretically this works, but how good will be the performance if there are 
Thousands of entries?
Anyway, I will try out.
Thanks again,
Ben




Shawn McKenzie schrieb:


On 05/10/2011 03:16 PM, Benedikt Voigt wrote:
   

Hi,
I'am very new to PHP, so please any comment is welcome.

I want to write a function in PHP, which takes X arguments and outputs a
value.
The functioning of this function should be stored in a db (mydb? or
better alternatives?)
The function would look up the result in the db based on the X arguments.

But how can I store X arguments and the corresponding output value?
If I limit the X arguments to a specific number like N=10, then I could
create N=10 +1 columns in a table.
But how should I do it if I don't want to limit myself to a fix number?

Thanks for any comment!
Ben
 

Two ways that come to mind:

1. If you don't need to search, join, etc. on any of the arguments in
the DB (*and never will need to*), then serialize the array and store it
in one column and the result in another.

2. Use two tables:

results
id  result
1   50
2   99

arguments
id  results_id  argument
1   1   800
2   1   999
3   1   3.14

Then you just join results.id on arguments.results_id in your query.

If you actually need to store the argument name then just add another
column called variable and change the argument column's name to value.


id  results_id  variable  value


   



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Re: [PHP] Re: Storing indefinite arrays in database

2011-05-11 Thread Benedikt Voigt

Thank you Jasper,

this also sounds like an interesting approach.
But creating tables on the fly brings me to the idea, that I can also 
enlarge one table on the fly.
Then I could consider the function as a matrice and store it in only one 
table, which can be enlarged dynamically.


I am very new to PHP and havn't programmed for a decade now.
But thank you all (Bastien, Shawn, Jasper) for your comments. Probably I 
will implement all and run then some articifial performance tests agains 
the different versions.

But this will take me weeks or months until I am so far.

And I hoped some new non-relational DB technology could solve the 
challenges I described, but probably not.

Cheers,
Ben


Jasper Mulder schrieb:


   

Date: Wed, 11 May 2011 22:15:21 +0200
From: benedikt.vo...@web.de
To: nos...@mckenzies.net
CC: php-general@lists.php.net
Subject: Re: [PHP] Re: Storing indefinite arrays in database

Thanks Shawn,

yes, your second idea works for me. The first one not, as I need to
search and join on it.
To continue your second idea with your example:

Arguments:
id results_id variable value
1 1 1 800
2 1 2 999
3 1 3 3.14

Results:
id result
1 50
2 99

The Arguments and Results table would be filled dynamically by user content.
In order to run a function, I have to do N times a join, whereas N is the 
number of arguments:

select result
from Results join Arguments as A1 join Arguments as A2 join Arguments as A3
on Results.id=A1.results_id and
on Results.id=A2.results_id and
on Results.id=A3.results_id and
where
A1.variable=1 and A1.value=800 and
A2.variable=2 and A2.value=999 and
A3.variable=3 and A3.value=3.14 and
A1.results_id=Results.results_id and
A2.results_id=Results.results_id and
A3.results_id=Results.results_id

Theoretically this works, but how good will be the performance if there are 
Thousands of entries?
Anyway, I will try out.
Thanks again,
Ben

 

Dear Ben,

Firstly, as this is my first post to this list I apologize for any etiquette 
mistakes.

I would like to suggest to you a different approach, which would be more 
dynamical:
First, you would have a table which stores the number of arguments of a certain 
entry, something like

record_id   num_of_arg

You would store the num_of_arg entry in a PHP variable, say $num.
Then you would proceed to use

   CREATE TABLE IF NOT EXISTS \'entries_.$num.\' ...some more code...

to create a table which can store precisely $num arguments per record.
Then you add it to that table using standard MySQL.
Effectively this groups all records into tables according to $num.

The only thing here is that you probably need to call the database two times:
  - first to get num_of_arg to be able to call onto the right table
  - second to get the data

But as the number of arguments would go into the thousands, no huge join would 
be necessary.
Only thing is, that you would have very wide tables (I don't know how wide 
MySQL can go).

Creating tables on-the-fly as necessary seems to be something you could 
consider,
but again I stress that I don't know performance details. There might be 
something quicker.

So far for my 2c. Hopefully, it is of some help.

Best regards,
Jasper Mulder

   




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[PHP] Storing indefinite arrays in database

2011-05-10 Thread Benedikt Voigt

Hi,
I'am very new to PHP, so please any comment is welcome.

I want to write a function in PHP, which takes X arguments and outputs a 
value.
The functioning of this function should be stored in a db (mydb? or 
better alternatives?)

The function would look up the result in the db based on the X arguments.

But how can I store X arguments and the corresponding output value?
If I limit the X arguments to a specific number like N=10, then I could 
create N=10 +1 columns in a table.

But how should I do it if I don't want to limit myself to a fix number?

Thanks for any comment!
Ben

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