Re: [cx-oracle-users] Feedback desired on types and binding

[Anthony T. <ant...@gm...>]

On 10/12/06, Amaury Forgeot d'Arc <ama...@gm...> wrote:
> Anthony Tuininga wrote:
> > The methods cursor.setinputsizes(), cursor.var() and cursor.callfunc()
> > accept types to indicate what sort of bind variable is desired. These
> > types are generally the types defined by the DB API but I have added a
> > number of additional ones to support data types supported by Oracle
> > but not covered by the DB API. There are a number of cases where the
> > type indicated by Oracle covers multiple Python types. This is seen
> > primarily in two places (that I am aware of at the moment). The first
> > is the desire to return integers from callfunc() and the second is the
> > desire to return unicode strings directly from cx_Oracle (rather than
> > have to decode them yourself). A couple of patches have been sent to
> > me to do both of these things by adding another set of high-level
> > types. The problem with this is that it further confuses the already
> > confused type hierarchy. So far all of the types are types from the
> > Oracle perspective only and I'd like to keep it that way. So, I have
> > an alternative suggestion which I'd like some feedback on: allow
> > setinputsizes(), var() and calfunc() to accept Python types and use
> > these to tweak the type of Python object that will be returned. In
> > other words
> >
> > cursor.callfunc("SomeFunction", int, (parm1, parm2))
> >
> > or
> >
> > cursor.setinputsizes(someparm = int)
> >
> > or
> >
> > cursor.var(int)
> >
> > In all of the above cases a NUMBER bind variable would be created but
> > whenever the value of the variable is acquired the type of object
> > returned would be an integer. The same thing would occur with unicode.
> >
> > Does this seem reasonable to you? Any comments appreciated. Thank you.
>
> +1.
> Most of the time, user code knows the datatype used by the database,
> and the desired python type, but doesn't want to care about the type
> of the intermediate OCI variable, as long as no information is lost.

Thank you. From this and the other comments it would appear this
change is supported. I'll see if I can make these changes for the next
release.

> BTW, is there a corresponding python type for LOB locators? file? StringIO?
> It may be necessary because cx_Oracle.STRING seems to be limited to 32K.

The corresponding Python type for LOB locators is str -- for those you
will have to use cx_Oracle.BLOB or cx_Oracle.CLOB as appropriate. Yes,
cx_Oracle.STRING (Oracle type of string) is limited to 32K so if you
need more you have to use cx_Oracle.CLOB.

> --
> Amaury Forgeot d'Arc
>
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