对 HSQLDB 2.3.0 的快照 50 执行以下查询时会产生错误。错误消息是“错误：派生表中的列名重复：INST_ID”
SELECT c.lastname, to_date_string(c.dob), i.itag|| ': ' ||
m.mrn, to_date_string(en.dofs),
to_date_string(en.dols), pa.payertag,
y.dxname, d.icd9, d.icd10, d.icd10name,
to_datetime_string(s.dos), r.cpt, r.rxname, p.lastname || ', ' ||
p.firstname
FROM Encounters AS en
INNER JOIN Clients AS c USING ( cli_id )
INNER JOIN Client_MRNs AS m ON c.defmrn_id = m.mrn_id
INNER JOIN Institutions AS i USING ( inst_id )
INNER JOIN Payers AS pa USING ( payer_id )
INNER JOIN Encounter_DXs AS x USING ( enc_id )
INNER JOIN Diagnoses AS d USING ( dx_id )
INNER JOIN DXSynonyms AS y ON d.defsyn_id = y.syn_id
INNER JOIN Services AS s USING ( enc_id )
INNER JOIN RXCodes AS r USING ( rx_id )
INNER JOIN Providers AS p USING ( prov_id )
WHERE (s.dos >= 56453 AND s.dos < 56461)
ORDER BY c.lastname, en.dofs, s.dos;
但是，当我执行相同的查询但将所有 USING 谓词替换为 ON ... = 短语时，它会成功执行：
SELECT c.lastname, to_date_string(c.dob), i.itag|| ': ' ||
m.mrn, to_date_string(en.dofs),
to_date_string(en.dols), pa.payertag,
y.dxname, d.icd9, d.icd10, d.icd10name,
to_datetime_string(s.dos), r.cpt, r.rxname, p.lastname || ', ' ||
p.firstname
FROM Encounters AS en
INNER JOIN Clients AS c ON c.cli_id = en.cli_id
INNER JOIN Client_MRNs AS m ON c.defmrn_id = m.mrn_id
INNER JOIN Institutions AS i ON i.inst_id = m.inst_id
INNER JOIN Payers AS pa ON pa.payer_id = en.payer_id
INNER JOIN Encounter_DXs AS x ON x.enc_id = en.enc_id
INNER JOIN Diagnoses AS d ON d.dx_id = x.dx_id
INNER JOIN DXSynonyms AS y ON d.defsyn_id = y.syn_id
INNER JOIN Services AS s ON s.enc_id = en.enc_id
INNER JOIN RXCodes AS r ON r.rx_id = s.rx_id
INNER JOIN Providers AS p ON p.prov_id = s.prov_id
WHERE (s.dos >= 56453 AND s.dos < 56461)
ORDER BY c.lastname, en.dofs, s.dos;
这是否按预期工作？我喜欢使用 USING，因为它可以减少冗长、简洁的代码。我现在不包括表的 DDL（但可以），因为查询很大并且涉及许多表，但是有三个表具有 INST_ID 字段。一个表将其作为主键，另外两个表具有外键。实际上，查询中的唯一区别是“ON”与“USING”。