Why are String Formatted Queries Considered So Magical?

[Carl Banks]

On Jun 27, 9:02 pm, Stephen Hansen <me+list/pyt... at ixokai.io> wrote:
> On 6/27/10 8:48 PM, Carl Banks wrote:
>
> > I don't know the exact details of all of these, but I'm going to opine
> > that at least some of these are easily expressible with a function
> > call API.  Perhaps more naturally than with string queries.  For
> > instance, set operations:
>
> > query1 = rdb_query(...)
> > query2 = rdb_query(...)
>
> > final_query = rdb_union(query1,query2)
>
> > or
>
> > final_query = query1&  query2
>
> But, see, that's not actually what's going on behind the scenes in the
> database. Unless your "query1" and "query2" objects are opaque
> pseudo-objects which do not actually represent results

That's exactly what they are.  Nothing is actually sent to the
database until the user starts retrieving results.  This is fairly
common thing for some interfaces to do.

For instance, OpenGL almost always returns immediately after a command
is posted without doing anything.  The driver will queue the command
in memory until some event happens to trigger it (maybe a signal from
the graphics that is is done processing commands, or the queue being
full, or an explicit flush request from the user).

Incidentally, OpenGL has its own DSL for per-vertex and per-pixel
operations (known as vertex and fragment shaders) that replaces an
older binary API.  I daresay it's a little less at risk for an
injection attack, seeing that the shaders run on the GPU and only run
simple math operations.  But you never know.


Carl Banks