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サブクエリを使用して結果セットの列を表すクエリを実行しようとしています。

select id_column1, id_column2, id_column3,
(select column4 from table2 where id in (id_column1, id_column2, id_column3)
order by id desc
limit 1) as column4
from table1
join table2 on table1.id = table2.id
join table3 on table2.id = table2.id
where clause...

私が持っているsqlalchemyの同等物は

order_state = aliased(Table1)
po_state = aliased(Table1)
proof_state = aliased(Table1)

subq = meta.Session.query(Table2.exception_message).\
  filter(Table2.entity_id.in_([Table3.id, Table4.id, Table5.id])).\
  order_by(Table2.id.desc()).\
  limit(1).label('exception')

query = meta.Session.query(
  Table3.po_number, Table4.id.label('po_id'), Order.id.label('order_id'),\
  Table5.id.label('proof_id'), order_state.description.label('order_state'),\
  po_state.description.label('po_state'), proof_state.description.label('proof_state'),
  Table3.order_placement_date, subq).\
  outerjoin(Table4, Table3.id == Table4.order_id).\
  outerjoin(Table5, Table4.id == Table5.po_id).\
  outerjoin(order_state, Table3.state_diagram_state_id == order_state.id).\
  outerjoin(po_state, Table4.state_diagram_state_id == po_state.id).\
  outerjoin(proof_state, Table5.state_diagram_state_id == proof_state.id).\
  filter(Table3.is_placed != 0).\
  filter(not_(Table3.po_number.contains('%-%'))).\
  filter(not_(Table3.state_diagram_state_id.in_(Table1.NONE_ORDER_EXCEPTIONS))).\
  filter(or_(Table3.state_diagram_state_id.in_(Table1.ORDER_EXCEPTIONS),\
    Table4.state_diagram_state_id.in_(Table1.PO_EXCEPTIONS),\
    Table5.state_diagram_state_id.in_(Table1.PROOF_EXCEPTIONS)))

クエリしている列をそのフィルターのパラメーターとして使用するSQL錬金術でサブクエリをどのように使用しますか?

とても有難い。

4

1 に答える 1

0

(参照された sqlfiddle に基づいて編集)

from sqlalchemy import create_engine

sql = """
CREATE TABLE Table1
     (
     id int primary key,
     type varchar(20),
     details varchar(30)
    );

CREATE TABLE Table2
     (
     id int primary key,
     type varchar(20),
     details varchar(30)
    );

CREATE TABLE Table3
     (
     id int primary key,
     type varchar(20),
     details varchar(30)
    );

CREATE TABLE Table4
     (
     id int primary key,
     entity_id int,
     type varchar(20),
     details varchar(30)
    );

INSERT INTO Table1 (type, details) values ('data1', 'details of data1');

INSERT INTO Table2 (type, details) values ('data2', 'details of data2');

INSERT INTO Table3 (type, details) values ('data3', 'details of data3');

UPDATE Table2 SET id = 2 where id = 1;
UPDATE Table3 SET id = 3 where id = 1;

INSERT INTO Table4 (entity_id, type, details) values (1, 'exception', 'err 1');
INSERT INTO Table4 (entity_id, type, details) values (2, 'exception2', 'err 2');
INSERT INTO Table4 (entity_id, type, details) values (3, 'exception3', 'err 3');

"""

e = create_engine("sqlite://", echo=True)

for stmt in sql.split(";"):
    e.execute(stmt.strip())

from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.ext.declarative import DeferredReflection
Base = declarative_base(cls=DeferredReflection)

class Table1(Base):
    __tablename__ = 'Table1'

class Table2(Base):
    __tablename__ = 'Table2'

class Table3(Base):
    __tablename__ = 'Table3'

class Table4(Base):
    __tablename__ = 'Table4'

Base.prepare(e)

from sqlalchemy.orm import Session
s = Session(e)

subq = s.query(Table4.type).filter(Table4.entity_id.in_([Table1.id, Table2.id, Table3.id]))
q = s.query(
        Table1.type,
        Table2.type,
        Table3.type,
        subq.label('table4type')
    ).join(Table2, Table1.id == Table2.id).join(Table3, Table2.id == Table3.id)
print q.all()
于 2013-10-22T03:46:01.057 に答える