Re: [Sqlalchemy-tickets] [sqlalchemy] #2587: flatten joined-inheritance join targets on individual tables

[sqlalchemy <mi...@zz...>]

#2587: flatten joined-inheritance join targets on individual tables
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      Reporter:  zzzeek       |      Owner:  zzzeek
          Type:  enhancement  |     Status:  new
      Priority:  medium       |  Milestone:  0.9.0
     Component:  orm          |   Severity:  very major - up to 2 days
    Resolution:               |   Keywords:
Progress State:  in queue     |
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Comment (by zzzeek):

 another thought.  push it into the compiler (copied from #2369, applies
 more closely here).

 {{{
 #!sql

 # nested join:

 SELECT
         a.x AS a_x, a.y AS a_y,
         b.x AS b_x, b.y AS b_y,
         c.x AS c_x, c.y AS c_y
 FROM a JOIN (
                 b JOIN c on b.id=c.id
         ) on a.id=b.id

 # currently, ORM would rewrite this as:

 SELECT
         a.x AS a_x, a.y AS a_y,
         anon_1.b_x AS anon_1_b_x,
         anon_1.b_y AS anon_1_b_y,
         anon_1.c_x AS anon_1_c_x,
         anon_1.c_y AS anon_1_c_y

 FROM a JOIN (
                 SELECT b.id AS b_id, b.x AS b_x, b.y AS b_y, c.x AS c_x,
 c.y AS c_y
                 FROM b JOIN c on b.id=c.id
         ) AS anon_1 on a.id=anon_1.b_id


 # but if we could get compiler to rewrite as:

 SELECT
         a.x AS a_x, a.y AS a_y,
         anon_1.b_x AS b_x,
         anon_1.b_y AS b_y,
         anon_1.c_x AS c_x,
         anon_1.c_y AS c_y
 FROM a JOIN (
                 SELECT b.id AS b_id, b.x AS b_x, b.y AS b_y, c.x AS c_x,
 c.y AS c_y
                 FROM b JOIN c on b.id=c.id
         ) AS anon_1 on a.id=anon_1.b_id


 }}}

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2587#comment:3>
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