[DB-SIG] PyGresSql help

Tom Bryan tbryan@server.python.net
Tue, 25 Jan 2000 07:51:58 -0500 (EST)

On Mon, 24 Jan 2000, Jim Johannsen wrote:

> I am trying to use PyGresSQL to connect Python and Postgress.   I have
> managed to connect to the db, but cannot update the database with a list
> or with strings.  I have tried the following code w/o success:
> cnx.query("INSERT INTO county VALUES(%s,%s,%s)")  %(Ldata[0], Ldata[1],
> Ldata[3])


> and countless variations of the above.  Every variation but the correct
> one.

I think that this is more of a generic Python syntax problem than a
database problem.  I would guess that the string interpolation must
occur inside of the function argument.  For example, 

Python 1.5.2 (#1, Apr 18 1999, 16:03:16)  [GCC pgcc-2.91.60 19981201 
(egcs-1.1.1  on linux2
Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam
>>> def foo(text):
...  print text
>>> foo("%s, %s, %s") % ('one','two','three')
%s, %s, %s
Traceback (innermost last):
  File "<stdin>", line 1, in ?
TypeError: bad operand type(s) for %
>>> foo( "%s, %s, %s" % ('one','two','three') )
one, two, three

So, I'd suggest the following.  (Note that the whitespace isn't really
necessary: I'm just trying to emphasize how the parentheses nest.)

cnx.query (
    "INSERT INTO county VALUES(%s,%s,%s)" % (
        Ldata[0], Ldata[1],Ldata[3]