Re: Database connections

Hi George

_____

From: George Weaver [mailto:georgew1(at)mts(dot)net]
Sent: 14 October 2003 14:58
To: pgadmin-support(at)postgresql(dot)org
Subject: [pgadmin-support] Database connections


In pgAdmin II, if I understand it correctly, the program
determines the databases present on the server using pg_Database when
the user selects Connect. I assume that the program then connects to a
specific database when one is chosen by the user from the database tree.

In a nutshell, yes.

As far as I can tell, this is done without using a User, System,
or File DSN.

Yes, this is called a DSN-less connection. All the DSN actually does is
store pre-determined settings that the driver can use when connecting to
the database, as well as the driver name itself. Those settings can also
be passed to the driver through the connection string, and the DSN name
omitted.

Can you direct me to a source of information or documentation
which describes how this is accomplished?

There is an example of some VB code that uses a DSN at
http://gborg.postgresql.org/project/psqlodbc/genpage.php?howto-visualbas
ic. The same code can be used DSN-less simply by modifying the
connection string - instead of

cn.Open
"DSN=<MyDataSourceName>;UID=<MyUsername>;PWD=<MyPassword>;Database=<MyDa
tabaseName>"

you might try something like:

cn.Open
"DRIVER={PostgreSQL};UID=<MyUsername>;PWD=<MyPassword>;Database=<MyDatab
aseName>"

pgAdmin also sets the following options in the connection string above
(they are in no particular order, and may be omitted to get the
defaults).

READONLY=0;PROTOCOL=6.4;FAKEOIDINDEX=0;SHOWOIDCOLUMN=0;ROWVERSIONING=0;S
HOWSYSTEMTABLES=0;CONNSETTINGS=;FETCH=100;SOCKET=4096;UNKNOWNSIZES=0;MAX
VARCHARSIZE=254;MAXLONGVARCHARSIZE=65536;OPTIMIZER=1;KSQO=1;USEDECLAREFE
TCH=0;TEXTASLONGVARCHAR=1;UNKNOWNSASLONGVARCHAR=0;BOOLSASCHAR=1;PARSE=0;
CANCELASFREESTMT=0;EXTRASYSTABLEPREFIXES=dd_;

Thanks for you help (and a super product!)

You're welcome.

Regards Dave.