PEAR::DB disconnect closes all database connections

[Sven Jacobs]

Dear newsgroup,

I've upgraded to PEAR::DB 1.6.5 recently. Unfortunately now the database
connection doesn't work as expected anymore :( The problems seems to be the
method disconnect(), which now closes the database connections of _all_
database objects. I ask myself if this is intentional or a bug. Below a
code example:

01 <?php
02   error_reporting (E_ALL);
03
04   require_once('D B.php');
05
06   define('DB_TYPE ',     'mysql');
07   define('DB_HOST ',     'localhost');
08   define('DB_PORT ',     3306);
09   define('DB_USER NAME', 'xxx');
10   define('DB_PASS WORD', 'yyy');
11   define('DB_DATA BASE', 'zzz');
12
13   function db_open()
14   {
15     $dsn = DB_TYPE . '://' . DB_USERNAME . ':' . DB_PASSWORD . '@' .
16     DB_HOST . ':' . DB_PORT . '/' . DB_DATABASE;
17     $db  = DB::connect($ds n);
18     return $db;
19   }
20
21   function a()
22   {
23     $db = db_open();
24
25     b();
26
27     echo 'query in a()<br />';
28     $test = $db->getAll('sele ct * from abc');
29     $db->disconnect() ;
30
31     if (DB::isError($t est))
32       echo $test->getMessage() . '<br /><br />' . $test->getDebugInfo() ;
33   }
34
35   function b()
36   {
37     $db = db_open();
38
39     echo 'query in b()<br />';
40     $test = $db->getAll('sele ct * from abc');
41     $db->disconnect() ;
42
43     if (DB::isError($t est))
44       echo $test->getMessage() . '<br /><br />' . $test->getDebugInfo() ;
45   }
46
47   a();
48 ?>

In function a() function b() is called which creates a local database
object, does some stuff on the database and then closes its connection.
That worked up to now. Since upgrading PEAR::DB it seems like the
disconnect() of the database object from b() also disconnects the object
from a() because I get the error "DB Error: no database selected" in row 28
of the script. If I comment out the call of b() at row 25 everything works
as expected. I was able to reproduce this behavior with the PHP version
4.3.8 and 5.0.1. Why does a method of a local object interfere with another
local object?!

--
Sincerely
Sven Jacobs

[Nikolai Chuvakhin]

Re: PEAR::DB disconnect closes all database connections

Sven Jacobs <sven.jacobs@we b.de> wrote in message
news:<cgnhh9$e1 f$00$1@news.t-online.com>...[color=blue]
>
> I've upgraded to PEAR::DB 1.6.5 recently. Unfortunately now the database
> connection doesn't work as expected anymore :( The problems seems to be the
> method disconnect(), which now closes the database connections of _all_
> database objects.[/color]
....[color=blue]
> Why does a method of a local object interfere with another local object?![/color]

It has NOTHING to do with objects and everything to do with underlying
database interface:

If a second call is made to mysql_connect() with the same arguments,
no new link will be established, but instead, the link identifier
of the already opened link will be returned. The new_link parameter
modifies this behavior and makes mysql_connect() always open a new
link, even if mysql_connect() was called before with the same
parameters.

Note: The new_link parameter became available in PHP 4.2.0

http://www.php.net/manual/en/function.mysql-connect.php

Now let's look at your code (compressed to highlight the point):

21 function a()
22 {
23 $db = db_open();
25 b();
29 $db->disconnect() ;
33 }
35 function b()
36 {
37 $db = db_open();
41 $db->disconnect() ;
45 }
47 a();

When function a() calls function b(), b() DOES NOT ESTABLISH A NEW
LINK TO THE DATABASE, but, rather, uses the one established by a().
So when b() closes the link, it closes the link established by a(),
and a() is no longer able to use it.

Cheers,
NC

[Sven Jacobs]

Re: PEAR::DB disconnect closes all database connections

Nikolai Chuvakhin wrote:
[color=blue]
> When function a() calls function b(), b() DOES NOT ESTABLISH A NEW
> LINK TO THE DATABASE, but, rather, uses the one established by a().
> So when b() closes the link, it closes the link established by a(),
> and a() is no longer able to use it.[/color]

So why did the code work before upgrading PEAR::DB? :-/ Did they pass the
new_link parameter and now removed it? Possible...

Can I safely remove all $db->disconnect() 's from my code and PHP will
disconnect from the db automaticly if the script execution ends?

--
Sincerely
Sven Jacobs

[Nikolai Chuvakhin]

Re: PEAR::DB disconnect closes all database connections

Sven Jacobs <sven.jacobs@we b.de> wrote in message
news:<cgnrbs$s2 9$01$1@news.t-online.com>...[color=blue]
>
> Can I safely remove all $db->disconnect() 's from my code and PHP will
> disconnect from the db automaticly if the script execution ends?[/color]

Yes, absolutely.

Cheers,
NC