How can I return a query in ResultProxy format when using SQLAlchemy ORM?

Question

I find ResultProxy more convenient to use than ORM results in some cases (by the docs I understand that I could iterate the columns in a full table). I tried this:

query = session.query(Table1)
results = [ResultProxy(a) for a in query]

... but fails with:

AttributeError: 'Table1' object has no attribute 'dialect'

zzzeek · Accepted Answer · 2013-08-13 14:04:26Z

1

you can't just instantiate a ResultProxy like that, it is specific to DBAPI cursors as well as contextual information regarding how the statement was constructed. Use Session.execute() to get one from query.statement. It wouldn't be hard to add a method to Query to provide the ResultProxy it works with directly, though.

answered Aug 13, 2013 at 14:04

zzzeek

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5 Comments

Yajo Over a year ago

How, then, do I get the ResultProxy it works with? Or any other way to fetch simple key-value pairs.

zzzeek Over a year ago

result_proxy = Session.execute(query.statement)

Yajo Over a year ago

that raises this exception "NoReferencedTableError: Foreign key associated with column 'seguimientos.empresa' could not find table 'datos' with which to generate a foreign key to target column 'id'"

zzzeek Over a year ago

would need a succinct and complete test case illustrating the query in question. that issue appears like something happening not during the query but within the mapper configuration stage.

Yajo Over a year ago

True. Thanks, I found the error. It works now. However I found an easier way to get what I wanted. I will put it as an answer below.

Yajo · Accepted Answer · 2013-09-06 07:30:52Z

0

Quick answer:

conn = engine.connect()
result_proxy = conn.execute(query.selectable)

Docs here.

You can also get a column index by its name...

col_index = query.selectable.columns.keys().index(id_column_name)

... and then get the result by its index:

first_row_col_content = query.all()[0][col_index]

answered Sep 6, 2013 at 7:30

Yajo

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