On 30/08/2010 02:38, Νίκος wrote:
On 29 Αύγ, 21:34, MRAB<pyt...@mrabarnett.plus.com> wrote:
It likes the values to be in a tuple. If there's one value, that's a
1-tuple: (page, ).
I noticed that if we are dealing with just a single value 'page' will
do, no need to tuple for 1-value.
it handles fine as a string.
I tried it with sqlite3, which it didn't like it. For consistency, and
compatibility with other SQL engines, I recommend that you always
provide a tuple.
cursor.execute('''SELECT hits FROM counters WHERE page = %s and
date = %s and host = %s''', page, date, host)
or python will not allow it cause it might think there are 4 args
isntead of two?
Not Python (the language) as such, but the method. As I said, it
expects the value(s) to be in a tuple.
If i dont parenthesize the execute method instead of getting 2
args(sql_query and tuple value) as it expects by deficition, it gets 4
args instead and thats why it fails? I need to know why ti fails. Is
that it?
If the SQL query contains placeholder(s), the .execute method expects
the value(s) to be provided in a tuple. It's as simple as that.
Also in here,
page, date, host is 3 separate variable values here
while
(page, date, host) is 3 separate variables values also but withing a
tuple. Is this correct?
It doesn't care about the variables as such, only their values. You're
putting the values into a tuple and then passing that tuple because
that's what the method wants.
cursor.execute(''' SELECT hits FROM counters WHERE page = '%s' and
date = '%s' and host = '%s' ''', (page, date, host))
Whats happens if i attempt to also quote by single or double quoting
the above although now i'm aware that .execute method does the quoting
for me?
The method will put in any quoting that's needed. If you also put in
quotes then that'll result in 2 sets of quoting, one inside the other
(or something like that).
Why make more work for yourself? Let the method do it for you, safely
and correctly!
I'am askign this because i'm tryong to see why
On 29 Αύγ, 21:34, MRAB<pyt...@mrabarnett.plus.com> wrote:
It likes the values to be in a tuple. If there's one value, that's a
1-tuple: (page, ).
I noticed that if we are dealing with just a single value 'page' will
do, no need to tuple for 1-value.
it handles fine as a string.
As I've said, for consistency I recommend that you always provide a
tuple because some SQL engines require it, and if you need to provide
multiple values then you'll need to anyway.
cursor.execute('''SELECT hits FROM counters WHERE page = %s and
date = %s and host = %s''', page, date, host)
or python will not allow it cause it might think there are 4 args
isntead of two?
Not Python (the language) as such, but the method. As I said, it
expects the value(s) to be in a tuple.
If i dont parenthesize the execute method instead of getting 2
args(sql_query and tuple value) as it expects by deficition, it gets 4
args instead and thats why it fails? I need to know why ti fails. Is
that it?
========================
Also in here,
page, date, host is 3 separate variable values here
while
(page, date, host) is 3 separate variables values also but withing a
tuple. Is this correct?
=========================
I'm asking this to see why
cursor.execute(''' SELECT hits FROM counters WHERE page = '%s' and
date = '%s' and host = '%s' ''' % (page, date, host) )
does work, while same thign qithout the quotes
cursor.execute(''' SELECT hits FROM counters WHERE page = %s and date
= %s and host = %s ''' % (page, date, host) )
doesn't. Dont know why but quotes somehopw confuse me both in strings
and sql_queries as well when it comes to substitutions.
Don't quote the placeholders yourself. Let the method do it.
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