handling the results of `session.execute`

[Jonathan Vanasco]

I've run into a few cases where I need to abandon the ORM and run `session.execute()` 

Usually... I'm doing a bunch of nested queries and only pull out a `count` or a few rows of 1-2 id columns. Writing in pure sql is faster (for me), gives me more control, and avoids having to do a baked-query.

Here's where my concern comes in -- `execute` returns a ResultProxy, and the first element is a RowProxy

so to get a count, I'm doing something like this:

    result = dbSession.execute(foo)

    result = list(result)[0][0]

This is... ugly.  and then I have to handle the logic to ensure I got a correct record back.

I'm wondering if anyone has figured a more elegant way to handle queries like this.

The best i can think of is using an shared function:

    result = extract_result_one(result)

    result = extract_result_first(result)

    result = extract_result_count(result)

and then just raise an appropriate error if there are too many (or no) rows.

anyone have a better idea?

[Mike Bayer]

On 02/05/2016 05:32 PM, Jonathan Vanasco wrote:
> I've run into a few cases where I need to abandon the ORM and run
> `session.execute()`

horrors

>
> Usually... I'm doing a bunch of nested queries and only pull out a
> `count` or a few rows of 1-2 id columns. Writing in pure sql is faster
> (for me), gives me more control, and avoids having to do a baked-query.
>
> Here's where my concern comes in -- `execute` returns a ResultProxy, and
> the first element is a RowProxy
>
> so to get a count, I'm doing something like this:
>
> result = dbSession.execute(foo)
> result = list(result)[0][0]
>
> This is... ugly. and then I have to handle the logic to ensure I got a
> correct record back.

why not call result.scalar() ?

>
> I'm wondering if anyone has figured a more elegant way to handle queries
> like this.
>
> The best i can think of is using an shared function:
>
> result = extract_result_one(result)
> result = extract_result_first(result)
> result = extract_result_count(result)
>
> and then just raise an appropriate error if there are too many (or no) rows.
>
> anyone have a better idea?

result.scalar() I think is what you're looking for



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[Jonathan Vanasco]

On Friday, February 5, 2016 at 6:03:11 PM UTC-5, Michael Bayer wrote:

horrors

i know :/

 

why not call result.scalar() ?

ignorance.

 

result.scalar() I think is what you're looking for

yep!