On Jul 27, 2010, at 11:49 AM, Jon Nelson wrote:

> I have two questions:
> 
> 1. I'm using postgresql, and I sometimes need to do column type
> conversions. In postgresql, this is normally done with the ::FOO
> operator where FOO is a data *type*.  Somtimes, but not usually, these
> data types are also available in function-like factories, but in this
> case that doesn't help me. SHould I use the cast(some_column, 'int')
> expression here?

::FOO in PG is their internal syntax for what CAST provides, yes.

> 
> 2. Frequently, I have a list of things upon which to operate. This
> list of things is not in a table, and I may want to call a function on
> this list of things. If I were writing the sql directly, I'd do
> something like this:
> 
> select function_foo(BAR.x) FROM (select value1, value2, value3) BAR(x);
> 
> What's the best way to emulate this with sqlalchemy?

there's a recipe for VALUES at 
http://www.sqlalchemy.org/trac/wiki/UsageRecipes/PGValues , the syntax you have 
above looks unfamiliar to me but VALUES will create a lexical "table" from a 
set of literals (or you can just modify that recipe to provide the exact syntax 
you want).

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