Re: [Phpgroupware-developers] Patches for PostgreSQL??

[Dani Oderbolz]

Kai Hofmann wrote:

> Hi Dani,
>
>  
>
> > When I used it, I got many "pg-atoi: Zero length string" errors.
> >
> > Does anybody know about the real status of this?
> >    
>
> I don't know the exact status of the postgre support, but
> I am working on SAPDB support - so the problem you mentioned
> sounds familar to me.
> The SQL statements itself are not a problem to my best knowledge,
> its more the  db_addslashes function that should be correctly
> adapted for the corresponding database.
> For SAPDB it looks like the following:
>
> /**
> * Escape strings before sending them to the database
> *
> * @param string $str the string to be escaped
> * @return string escaped sting
> */
> function db_addslashes($str)
> {
>  return str_replace("'","''",$str);
> }
>
> thats because in SAPDB as well as in SYBASE databases (and ADABAS D I think)
> a ' will be escaped by using it two times ''.
>
> Replacing it with "NULL" is not what you really want. Maybe there are other
> things
> that have to be escaped by the addslashes function like \ or / etc.
> but this depends on the database.
> I have not tested the postgre support for now. But somebody around should
> have it up and running.
I guess you are talking about something different
(while addslashed might be the proper place to put my fix).
The problem is PostgreSQLs treatment of the string ''.
If say, you have a coulmn id, which is of type int,
and you write:
Select * from table Where id=''
(This is a type of query that Phpgroupware does often, for exaple if you 
want to add new User Groups.)
then Postgres tries to treat '' like a number, which it can't.
Therefore, you have to replace '' which NULL (the intention of '' is to 
get a NULL,
but this is not the same thing!)
Actually, its not the same thing for any DB! (But most others don't 
complain).

Thats why I am replacing all '' by NULL (which seems to work).

Cheers, Dani