engelbert.gruber@[...].at wrote:
>  On Sun, 16 Apr 2006, Andy Todd wrote:
>  
> > Lukasz Szybalski wrote:
> >> On Sat, 2006-04-15 at 12:01 +0000, Andrew Chambers wrote:
> >>> * Lukasz Szybalski <szybalski@[...].com> [2006-04-14 12:00:09 -0500]:
> >>>
> >>>> INSERT INTO table_x( body)VALUES( '%s')" %  (body)
> >>>>
> >>>> this body is a string that varies in size. I keep getting an error if
> >>>> the size of body is longer then 255, and if its smaller everything
> >>>> goes smooth. Is this syntax correct? should '%s' be something else?
> >>> What is the datatype of body?  It sounds like it is CHAR(255).  Can you
> >>> change this to be TEXT?
> >>>
> >> Yes it is text.
> >> mysql> describe table_x;
> >> +----------+---------+------+-----+---------+-------+
> >> | Field    | Type    | Null | Key | Default | Extra |
> >> +----------+---------+------+-----+---------+-------+
> >> | id | int(11) |      | PRI | 0       |       |
> >> | body     | text    | YES  |     | NULL    |       |
> >> +----------+---------+------+-----+---------+-------+
> >>
> >> Would some kind of characters that are passed in had something to do
> >> with the error, maybe EOF or something similar?
> >>
> >> The string that is passed in is from xml node. For debugging i made it
> >> return str(body), but that didn't change anything.
> >>
> >> Are there any other database/%s related requirements?
>  
>  not the way you pass it (as i understand it python first does "%" 
>  replacement and then passes the string.
>  
> > My observation is that with MySQLdb %s is a parameter substitution value
> > not a string substitution indicator.
> >
> > What happens when you try something like this;
> >
> >>>> stmt = "INSERT INTO table_x (body) VALUES (%s)" # [1]
> >>>> cursor.execute(stmt, (body,))
> > [1] note that there are no quote marks around the %s
>  
>  this works here (debian testing, python 2.3.5, 4.0.21) 
>  ::
>  
>  import MySQLdb
>  """
>  create table table_x (
>     id int auto_increment primary key,
>     body text
>     )
>  """
>  db = MySQLdb.connect(passwd="",db="test")
>  c = db.cursor()
>  body = "0....5...."*28
>  sql = "INSERT INTO table_x (body) VALUES('%s')"
>  c.execute( sql % (body))
>  c.execute("select body from table_x")
>  for row in c.fetchall():
>       print len(row[0])
>  
>  i wont bet on fetching 1Mb.
>  
>  cheers

You've just repeated the original poster's code. As I suggested the 
problem is that he's using string substitution when he should be using 
parameter substitution. In these cases %s means two completely different 
things.

Please read the sections on 'paramstyle' and the cursor '.execute' 
method in the DB-API 2.0 definition [1].

Regards,
Andy

[1] http://www.python.org/dev/peps/pep-0249/
-- 
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