我有这个sql请求：
SELECT pl.*, l.loyer, l.charges, l.locataire_id, laire.nom, laire.prenom,
l.chambre_id, c.numero, c.etage, c.maison_id, m.titre_crm
FROM
(
SELECT spl.id, spl.location_id, spl.mois, spl.annee, spl.loyer_paye
from locations sl
LEFT JOIN
(
SELECT * FROM paiement_loyer
union
SELECT 9999, usl.id, (MONTH(NOW())-1), YEAR(NOW()), 0
FROM locations usl
WHERE usl.id not in (SELECT location_id FROM paiement_loyer) ||
(select count(*) FROM paiement_loyer
WHERE location_id = usl.id AND annee = YEAR(NOW())
AND mois=(MONTH(NOW())-1) ) = 0
) spl ON sl.id = spl.location_id
where sl.date_debut <= CURDATE() && CURDATE() <= sl.date_fin
) pl
JOIN locations l ON pl.location_id = l.id
JOIN locataires laire ON l.locataire_id = laire.id
JOIN chambres c ON l.chambre_id = c.id
JOIN maisons m ON c.maison_id = m.id
ORDER BY trim(upper(m.titre_crm)), c.numero, annee, mois
我想简化它，请问您有什么想法吗？
尝试清理它。请注意，我认为第一个左外部连接可能可以交换为内部连接。
我已经将第二个 UNIONed 查询交换为 2 个查询，对于这些查询，我已将它们更改为使用左外部连接，然后检查是否不匹配
SELECT pl.id, pl.location_id, pl.mois, pl.annee, pl.loyer_paye,
l.loyer, l.charges, l.locataire_id, laire.nom, laire.prenom,
l.chambre_id, c.numero, c.etage, c.maison_id, m.titre_crm
FROM
(
SELECT spl.id, spl.location_id, spl.mois, spl.annee, spl.loyer_paye
FROM locations sl
LEFT OUTER JOIN
(
SELECT id, location_id, mois, annee, loyer_paye
FROM paiement_loyer
UNION
SELECT 9999, usl.id, (MONTH(NOW())-1), YEAR(NOW()), 0
FROM locations usl
LEFT OUTER JOIN paiement_loyer pl1
ON usl.id = pl1.location_id
WHERE pl1.location_id IS NULL
SELECT 9999, usl.id, (MONTH(NOW())-1), YEAR(NOW()), 0
FROM locations usl
LEFT OUTER JOIN paiement_loyer pl2
ON usl.id = pl1.location_id
AND pl2.annee = YEAR(NOW())
AND pl2.mois=(MONTH(NOW())-1)
WHERE pl2.location_id IS NULL
) spl ON sl.id = spl.location_id
WHERE CURDATE() BETWEEN sl.date_debut AND sl.date_fin
) pl
JOIN locations l ON pl.location_id = l.id
JOIN locataires laire ON l.locataire_id = laire.id
JOIN chambres c ON l.chambre_id = c.id
JOIN maisons m ON c.maison_id = m.id
ORDER BY TRIM(UPPER(m.titre_crm)), c.numero, pl.annee, pl.mois