Em Sáb 18 Fev 2006 17:51, Danny Yoo escreveu:
> > db=MySQLdb.connect(host='localhost',user='root',passwd='081300',db='tut')
> > cursor=db.cursor()
> > name = raw_input("Please enter a Name: ")
> > color =raw_input("Please enter a Color: ")
> > cursor.execute("""INSERT INTO horses(name,color)
> > VALUES("%s","%s")"""%(name,color))
>
> ^^^^^^^^^
>
> Hi Servando,
>
> Don't do this: don't try to interpolate the variables yourself, but pass
> the parameters as part of the execution call:
>
> http://mail.python.org/pipermail/tutor/2003-April/022010.html
It's interesting, but I'm missing something. What does it mean, a "prepared
statement"? I can see *why" to use it, but not *what* it is. But wait... is
it simply a difference between concatenating variables and putting them
"inline" in the string? So the on the second line of code below mysql will
know for sure that c is the wanted value for xname, even if it is something
that should be quoted?
a="select xname,sname from people where xname='"+c+"'"
cursor.execute("select xname,sname from people where xname=%s", c)
> > this script runs without error and does not affect the database in any
> > manner. The database does exist. User/Password are valid. I have run
> > the above script , unchanged, on both Macintosh and Ubuntu with success.
>
> Are you familiar with database transactions? Look at the description of
> close() in the Python DB API:
>
> """Close the connection now (rather than whenever __del__ is
> called)... Note that closing a connection without
> committing the changes first will cause an implicit
> rollback to be performed."""
>
> (http://www.python.org/peps/pep-0249.html)
>
> Does this last sentence ring some bells? *grin*
>
> Newest versions of the MySQLdb module do NOT autocommit anymore. You have
> to commit at the end or else you're not going to see any mutation affect
> the database: every change you make will just roll back.
Even with MyIsam tables, which are not transactional?
Tiago.
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