RE: [Apc-aa-coders] getDB and freeDB

[Mitra <mi...@ea...>]

You could be correct, I'm not sure if PHP caches connections.

What I KNOW to be bad is using $db, $db2, and $db3 because if in the 
middle of using $db to fetch records, then you use a function call 
(for example to turn and id into a name) and this uses the same $db 
then you break things. Its a recipe for bugs.

So I see two solutiosn

1:  $db = new DB_AA() ;    use the $db ;
or
2: $db = getDB; use the $db  ; freeDB($db)

Actually, I can't see how #1 (or the current way of doing things) can 
reuse database connections, because how does PHP know when you've 
finished with the SELECT?

yes - there could be a problem with "return" without freeing the db, 
but I'd rather have an occasional inefficiency, than a big problem 
with possible bugs. I'm not making any mass changes, just changing 
the code as I work on it, so I think it will be easy to do it 
carefully.

- Mitra


At 8:56 PM +0100 17/2/03, Jakub Adamek wrote:
>Mitra,
>
>the PHPlib approach of having the DB connection and recordset in one
>class is a bit strange. The result is, we should create a new recordset
>DB_AA for each SELECT query. The current approach of using one recordset
>everywhere is perhaps caused by the name DB_AA which looks like database
>and usually only one database is used. It is surely wrong.
>
>I am not sure, but my idea was that the persistent connections are kept
>by PHP and not by individual scripts and thus creating a new DB_AA would
>waste no time as it uses always only finds a persisten connection? It
>this is the case, getDB and freeDB are not needed because they only
>duplicate this behavior.
>
>One more remark: Your approach seems to me a bit uncovenient. The
>problem is you must call freeDB() every time you exit any function.
>Surely somebody will forget to do so at least in some places where he or
>she uses "return". In C++ such things are solved by constructors and
>destructors, but PHP has no destructors. On the other hand this will
>perhaps do no much damage as the not-freed DBs will be closed as the
>script finishes.
>
>Jakub
>
>>  -----Original Message-----
>>  From: apc...@li...
>>  [mailto:apc...@li...] On Behalf Of Mitra
>>  Sent: Sunday, February 16, 2003 10:56 AM
>>  To: apc...@so...
>>  Subject: [Apc-aa-coders] getDB and freeDB
>>
>>
>>  One change of note is to add functions getDB and freeDB so that there
>>  is no longer the risk of one operation mucking up an in-process DB
>>  action.
>>
>>  Basically instead of trying to decide whether to use globals $db $db2
>>  or $db3 instead just  go
>>
>>
>>  $db = getDB()
>>  $db->normal db ops
>>  freeDB($db)
>>
>>  The system keeps an array of unused $db's so that we still get the
>>  advantages of keeping connections open.
>>
>>  I have NOT incorporated this into the existing code, - since to do so
>>  would inevitably involve making one or more mistakes that broke
>>  something!,  but I will do whenever I'm working on something.
>>
>>  - Mitra
>>
>>  --
>>  Mitra Technology Consulting -  www.mitra.biz -
>>  mi...@mi... 02-6684-8096  or 0414-648-0722
>>
>>  Life is a Mystery to be Lived, not a Problem to be Solved
>>
>>
>>
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-- 
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02-6684-8096  or 0414-648-0722 

Life is a Mystery to be Lived, not a Problem to be Solved