[TYPO3-dev] External DB connection inside an extension ?

[Stephane]

Hi Typo'Gurus

I nedd your help. I have a question about external db connection inside 
typo3 extension.

I'm writing an extension who needs to get data from another db (I know, 
accessing directly to external db is not the best way, but it's the more 
efficient approach (for speed) than I found after testing SOAP (SOAP is 
very very very slow) and Co).

Then, in my extension, I open a new connection to my external db via 
mysql_connect command. I'm able to get all necessaries datas with 
queries ... no problem .. until here.

The problem come just after. After this mysql_query on external db, I 
don't know why but I lost the connection to Typo3 db :(.

$GLOBALS['TYPO3_DB']->sql_num_rows return always return 0 (records exist 
of course), until I call back $GLOBALS['TYPO3_DB']->connectDB().
After this call I could again access to Typo3 db.

Sample code / algo :

$mylink = mysql_pconnect($server, $username, $password);
$mydb = mysql_select_db($dbname, $mylink);
...
$result = mysql_query($myquery, $mylink);
[ ok I'm able to get external records ]
...
$res = $GLOBALS['TYPO3_DB']->exec_SELECTquery('*', $this->table, 
$whereClause);
[always = 0 :( ]
...
$GLOBALS['TYPO3_DB']->connectDB();
[now it's ok again, I could access to Typo3 db (normal I create a new 
link ressource) ... :s ]

I have try to use also "datasources" and "adob" approach (as done in 
rlmp_extdbauth for example) instead of "direct php approach", but with 
the same result :(. I try also pconnect or not, using 
t3lib_DB::sql_pconnect functions ... a lot of test but without better 
results ... Typo3 seems to use current active database, and not the 
$link information

I'm using Typo3 4.2.1 and develop a service extension ...

What is wrong in my approach ? It's a Typo3 know issue (with a solution 
;)) or a problem on my php/mysql configuration ?

Thanks a lot for your help (and sorry for my english)

BR

Stef