I'm seeing an odd (bug?) issue with performing selects with alias'd joins,
using a postgres db.
db.define_table('fqdn_word_part',
Field('word', 'string', unique=True)
)
db.define_table('fqdn_word_combine',
Field('fqdn_id', 'reference fqdn'),
Field('fqdn_word_part_id', 'reference fqdn_word_part'),
Field('place', 'integer')
)
aliases created;
>>> first
<Table first (id,fqdn_id,fqdn_word_part_id,place)>
>>> second
<Table second (id,fqdn_id,fqdn_word_part_id,place)>
>>> firstp
<Table firstp (id,word)>
>>> secondp
<Table secondp (id,word)>
...selecting a record:
db(firstp.word == 'google').select(firstp.word,
join=(first.on(first.fqdn_word_part_id==firstp.id)))
...generates the correct SQL:
SELECT firstp.word
FROM fqdn_word_part AS firstp
JOIN fqdn_word_combine AS first ON (first.fqdn_word_part_id = firstp.id)
WHERE (firstp.word = 'google');
...selecting a record using a self-join:
db(firstp.word == 'google')(secondp.word == 'com').select(firstp.word,
secondp.word,
join=(first.on(first.fqdn_word_part_id==firstp.id),second.on(second.fqdn_word_part_id==secondp.id)))
...generates SQL with a syntax error:
SELECT firstp.word, secondp.word
FROM fqdn_word_part AS firstp, fqdn_word_part AS secondp
JOIN fqdn_word_combine AS first ON (first.fqdn_word_part_id = firstp.id)
JOIN fqdn_word_combine AS second ON (second.fqdn_word_part_id = secondp.id)
WHERE ((firstp.word = 'google') AND (secondp.word = 'com'));
ProgrammingError: ('ERROR', '42P01', 'invalid reference to FROM-clause
entry for table "firstp"')
I can re-arrange the SQL to work correctly:
SELECT firstp.word, secondp.word
FROM fqdn_word_part AS firstp
JOIN fqdn_word_combine AS first ON (first.fqdn_word_part_id = firstp.id),
fqdn_word_part AS secondp JOIN fqdn_word_combine AS second ON
(second.fqdn_word_part_id = secondp.id)
WHERE ((firstp.word = 'google') AND (secondp.word = 'com'));
Is there a more effective way to do this with the DAL?
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