V následujícím dotazu se zobrazuje chyba:
SELECT DISTINCT UNIQUE_ID as uid, CONFIDENCE_IS_SAME FROM ( (SELECT UNIQUE_ID, CONFIDENCE_IS_SAME, FIRST_NAME, LAST_NAME, POSTAL_CODE FROM DANIEL.UNIQUE_PHYSICIAN WHERE DANIEL.UNIQUE_PHYSICIAN.FIRST_NAME = "" AND DANIEL.UNIQUE_PHYSICIAN.LAST_NAME = "" AND DANIEL.UNIQUE_PHYSICIAN.IS_ROOT_PHYS = 0 AND DANIEL.UNIQUE_PHYSICIAN.POSTAL_CODE = "") INNER JOIN (SELECT MAX(CONFIDENCE_IS_SAME) OVER (PARTITION BY ROOT_ID) max_conf FROM DANIEL.UNIQUE_PHYSICIAN WHERE DANIEL.UNIQUE_PHYSICIAN.FIRST_NAME = "" AND DANIEL.UNIQUE_PHYSICIAN.LAST_NAME = "" AND DANIEL.UNIQUE_PHYSICIAN.IS_ROOT_PHYS = 0 AND DANIEL.UNIQUE_PHYSICIAN.POSTAL_CODE = "") ON CONFIDENCE_IS_SAME = max_conf);
Odpověď
Potřebujete alias pro obě odvozené tabulky. A vnější pár kolem from
klauzule je k ničemu.
SELECT DISTINCT t1.unique_id AS uid, t1.confidence_is_same FROM ( --<< only one opening parenthesis SELECT unique_id, confidence_is_same, first_name, last_name, postal_code FROM daniel.unique_physician WHERE daniel.unique_physician.first_name = "" AND daniel.unique_physician.last_name = "" AND daniel.unique_physician.is_root_phys = 0 AND daniel.unique_physician.postal_code = "" ) t1 ---<< the alias for the derived table is missing INNER JOIN ( SELECT max(confidence_is_same) OVER (PARTITION BY root_id) max_conf FROM daniel.unique_physician WHERE daniel.unique_physician.first_name = "" AND daniel.unique_physician.last_name = "" AND daniel.unique_physician.is_root_phys = 0 AND daniel.unique_physician.postal_code = "" ) t2 ON t1.confidence_is_same = t2.max_conf
Spojení ale na prvním místě není potřeba. Váš dotaz lze zjednodušit na:
SELECT DISTINCT t1.unique_id AS uid, t1.confidence_is_same FROM ( SELECT unique_id, confidence_is_same, max(confidence_is_same) OVER (PARTITION BY root_id) max_conf FROM daniel.unique_physician unq WHERE unq.first_name = "" AND unq.last_name = "" AND unq.is_root_phys = 0 AND unq.postal_code = "" ) t1 where confidence_is_same = max_conf;
Není třeba vybrat first_name
, last_name
a postal_code
ve vnitřním výběru, protože je nepoužíváte ve vnějším výběru. Díky tomu může být dotaz potenciálně efektivnější.
Navíc podmínka unq.last_name = ""
nebude dělat to, co si myslíte, že dělá. Oracle nemá „prázdný řetězec“ „. Řetězec s nulovou délkou (""
) bude uložen jako NULL
, takže to, co opravdu chcete, je pravděpodobně:
SELECT DISTINCT t1.unique_id AS uid, t1.confidence_is_same FROM ( SELECT unique_id, confidence_is_same, max(confidence_is_same) OVER (PARTITION BY root_id) max_conf FROM daniel.unique_physician unq WHERE unq.first_name is null AND unq.last_name is null AND unq.is_root_phys = 0 AND unq.postal_code is null ) t1 where confidence_is_same = max_conf;