LEFT JOIN 导致重复行 - ORACLE

Question

我正在使用 WITH 子句编写子查询，并将其加入主查询。主查询的结果集为 332 条记录，子查询的结果集为 302 条记录。如果我对主查询执行 LEFT JOIN 子查询，我希望得到 332，但我得到了 336。我已经检查了主查询和子查询的重复项，特别是重复的记录和重复项不独立存在于查询中，为什么它们出现在连接中？

WITH FacOwner AS(
    SELECT 
        facility_id_fk, company,
        contact_first_name, contact_last_name,
        contact_title, contact_address1, contact_address2,
        contact_city, contact_state, contact_zipcode_five,
        contact_zipcode_four, contact_phone_number,
        
        sig_first_name, sig_last_name, 
        sig_title, sig_email,
        sig_address1, sig_address2, sig_city, sig_state, 
        sig_zipcode_five, sig_zipcode_four
        
        FROM Contacts
        WHERE Facility_Role = 'Owner'
)

SELECT 
    fg.facility_id_fk,
    fg.general_id_pk,
    fg.facility_name,
    fg.facility_status,
    fg.facility_type,
    fg.landfill_class,
    fg.dshw_staff_person,
    fg.ownership_type,
    loc.county,
    loc.facility_address_street,
    loc.facility_address_city,
    loc.health_department,
    
    FacOwner.company as Owner_Company, (FacOwner.contact_first_name || ' ' || FacOwner.contact_last_name) as OwnerName,  
    FacOwner.contact_title as OwnerTitle, (FacOwner.contact_address1 || FacOwner.contact_address2) as OwnerAddress,
    FacOwner.contact_city as OwnerCity, FacOwner.contact_state as OwnerState, (FacOwner.contact_zipcode_five || '-' || FacOwner.contact_zipcode_four) as OwnerZipcode,
    FacOwner.contact_phone_number as OwnerPhoneNumber,
    
    FacOwner.sig_first_name || ' ' || FacOwner.sig_last_name as OwnerCertSigName,
    FacOwner.sig_title as OwnerCertSigTitle, FacOwner.sig_email as OwnerCertSigEmail,
    (FacOwner.sig_address1 || ' ' || FacOwner.sig_address2) as OwnerCertSigAddress, FacOwner.sig_city as OwnerCertSigCity, FacOwner.sig_state as OwnerCertSigState, 
    (FacOwner.sig_zipcode_five || '-' || FacOwner.sig_zipcode_four) as OwnerCertSigZipcode

FROM facility_general fg
LEFT JOIN facility_location loc ON loc.facility_id_fk = fg.general_id_pk
LEFT JOIN FacOwner on FacOwner.facility_id_fk = fg.general_id_pk
ORDER BY fg.facility_id_fk;

Answer 1

没有代表性的数据，只能帮你解决问题。要确定问题，请从以下查询开始。

是否所有四列 return 都是相同的数字？

WITH FacOwner AS(
    SELECT 
        facility_id_fk, company,
        contact_first_name, contact_last_name,
        contact_title, contact_address1, contact_address2,
        contact_city, contact_state, contact_zipcode_five,
        contact_zipcode_four, contact_phone_number,
        
        sig_first_name, sig_last_name, 
        sig_title, sig_email,
        sig_address1, sig_address2, sig_city, sig_state, 
        sig_zipcode_five, sig_zipcode_four
        
        FROM Contacts
        WHERE Facility_Role = 'Owner'
)
SELECT count(*), count(distinct fg.general_id_pk), 
count(distinct FacOwner.facility_id_fk),
count(distinct loc.facility_id_fk)
FROM facility_general fg
LEFT JOIN facility_location loc ON loc.facility_id_fk = fg.general_id_pk
LEFT JOIN FacOwner on FacOwner.facility_id_fk = fg.general_id_pk
ORDER BY fg.facility_id_fk;

LEFT JOIN 导致重复行 - ORACLE

LEFT JOIN resulting in duplicate row - ORACLE

sql

oracle11g