Linqは外部結合を残し、多くのレコードに戻ってきたユニオンを返します

Question

linqクエリにはうまくいきますが、正しいレコードが得られていないストアドプロシージャを変換しています。 ストアドプロシージャは、次のようになります。私が持っている

SELECT isnull(a.CertificationId, cc.CertificationId) as CertificationId, 
    isnull(a.cipcode, cc.CipCode) as CipCode,isnull(a.Credential, lc.Credential) as Credential, 
    lc.LicensingCertificationProgram, lc.IssuingOrganization, isnull(a.ab, '') as ab 
FROM  enrCertificationCipCodes CC INNER JOIN 
    lkpCertifications lc ON CC.CertificationId = lc.CertificationId 
    left join 
     (SELECT pc.CertificationId, 
     cc.CipCode, 
     lc.Credential, 
     lc.LicensingCertificationProgram, 
     lc.IssuingOrganization, ab = 'Yes', 
     pc.psn 
      FROM  enrCertificationCipCodes CC INNER JOIN 
      lkpCertifications lc ON CC.CertificationId = lc.CertificationId 
      inner join (select * from enrProgramCertifications where PSN = @PSN) PC on cc.CertificationId = pc.CertificationId) as a on a.CertificationId = cc.CertificationId 
where cc.CipCode = @CipCode 
union 
select pc.CertificationId as CertificationId, p.cipcode as CipCode, other as Credential,'' as LicensingCertificationProgram, 
    '' as IssuingOrganization, 'Yes' as ab 
from (select * from enrProgramCertifications where CertificationId = '99999') pc join enrProgram p on pc.PSN = p.PSN 
    where p.CIPCode = @CipCode and p.PSN = @PSN 
    Union 
select '99999' as CertificationId, @CipCode as CipCode, 'Other' as Credential,'' as LicensingCertificationProgram, '' as IssuingOrganization, '' as ab 
order by ab desc, Credential 

LINQクエリは、結果は私が左結合されたテーブルから複数の行を取得していますということです

var t = ((from a in LkpCertifications 
     join d in EnrProgramCertifications on a.CertificationId equals d.CertificationId into ad 
       from d in ad.DefaultIfEmpty() 
       join c in EnrCertificationCipCodes on a.CertificationId equals c.CertificationId 
       where c.CipCode == "52.1999" 
       select new { 
       CertificationId = a.CertificationId, 
       CipCode = c.CipCode, 
       Credential = a.Credential, 
       Licensing = a.LicensingCertificationProgram, 
       IssuingOrganization = a.IssuingOrganization, 
       Psn = d.PSN != null ? d.PSN : 0, 
       ab = d.PSN != null ? "Yes" : "" 
       }) 
       .Union (from k in EnrProgramCertifications 
       join l in LkpCertifications on k.CertificationId equals l.CertificationId where k.PSN == 19480 
       select new{ 
       CertificationId = k.CertificationId, 
       CipCode = "52.1999", 
       Credential = k.Other, 
       Licensing = l.LicensingCertificationProgram, 
       IssuingOrganization = l.IssuingOrganization, 
       Psn = k.PSN != null ? k.PSN : 0, 
       ab = k.PSN != null ? "Yes" : "" 
       })).ToList(); 

t.Dump(); 

です。 PSN番号で修飾して左結合テーブルから行を制限しようとすると、lkpCertificationsテーブルから結果が得られません。 lkpCertificationにはすべての認証が含まれており、enrProgramCertificationsは注文と注文詳細設定のように選択された証明書のみを保持します。

私は19480.

任意のアイデアのPSNで0 PSNと、単一の55レコードにのみ単一の項目54を取得する必要があります

ようなので、私の現在の結果が見えます問題？

Answer 1

私は、左側の外部結合を返すためにdefaultifempty（）というオブジェクトにカップル結合を使用することでこの問題を解決できました。

   certs = (from a in _context.LkpCertifications 
        join d in _context.EnrProgramCertifications on a.CertificationId equals d.CertificationId into ad 
        from d in ad.DefaultIfEmpty() 
        join c in _context.EnrCertificationCipCodes on a.CertificationId equals c.CertificationId into ac 
        from c in ac.DefaultIfEmpty() 
        where c.CipCode == CIP || d.Psn == Psn 
        select new vmManageCertifications 
         { 
         Psn = d.Psn == Psn ? d.Psn : 0, 
         Cipcode = c.CipCode == null ? "0" : c.CipCode, 
         CertificationId = a.CertificationId, 
         Credential = a.Credential == "Other" ? d.Other : a.Credential, 
         LicensingCertificationProgram = a.LicensingCertificationProgram, 
         IssuingOrganization = a.IssuingOrganization, 
         ProgramCertified = d.Psn == Psn ? true : false 
         }).ToList().GroupBy(i => i.CertificationId).Select(group => group.First()).OrderByDescending(i => i.ProgramCertified);