我正在为 SQL Server 2008 R2 开发 TSQL 查询。我正在尝试开发此查询来识别一条记录/客户。由于其中一些值为 NULL，因此我目前正在对大多数表执行 LEFT JOINS。但 LEFT JOIN 的问题是，现在我为某些客户端获得 > 1 条记录。
但是，如果我将其更改为 INNER JOIN，则某些客户端将被完全排除，因为它们的这些列具有 NULL 值。如何将查询结果限制为只有一条记录/客户端，而不管 NULL 值如何？如果存在非 NULL 值，那么我希望它选择具有非 NULL 值的记录。
这是我当前的一些输出：
group_profile_id profile_name license_number is_accepting is_accepting_placement managing_office region vendor_name vendor_id applicant_type Office Address status_description Cert Date2 race ethnicity_desc religion
9CD932F1-6BE1-4F80-AB81-0CE32C565BCF Atreides Foster Home 1 Atreides1 1 Yes Manchester, NH Gulf Atlantic Atreides1 00000007 Treatment Foster Home 4042 Arrakis Avenue, Springfield, VT 05156 Open/Re-opened 2011-06-01 00:00:00.000 NULL NULL NULL
DCE354D5-A7CC-409F-B5A3-89BF664B7718 Averitte, Leon and Sandra 00000044 1 Yes Birmingham, AL Gulf Atlantic AL Averitte, Leon and Sandra 00000044 Treatment Foster Home 3816 5th Avenue, Bessemer, AL 35020, (205)482-4307 Open/Re-opened 2011-08-05 00:00:00.000 NULL NULL NULL
DCE354D5-A7CC-409F-B5A3-89BF664B7718 Averitte, Leon and Sandra 00000044 1 Yes Birmingham, AL Gulf Atlantic AL Averitte, Leon and Sandra 00000044 Treatment Foster Home 3816 5th Avenue, Bessemer, AL 35020, (205)482-4307 Open/Re-opened 2011-08-05 00:00:00.000 Caucasian/White Non Hispanic NULL
AD02A43C-6F38-4F35-8C9E-E12422690BFB Bass, Matthew and Sarah 00000076 1 Yes Jacks on, MS Central Gulf Coast MS Bass, Matthew and Sarah 00000076 Treatment Foster Home 506 Eagelwood Drive, Florence, MS 39073, (601)665-7169 Open/Re-opened 2011-04-01 00:00:00.000 NULL NULL NULL
AD02A43C-6F38-4F35-8C9E-E12422690BFB Bass, Matthew and Sarah 00000076 1 Yes Jackson, MS Central Gulf Coast MS Bass, Matthew and Sarah 00000076 Treatment Foster Home 506 Eagelwood Drive, Florence, MS 39073, (601)665-7169 Open/Re-opened 2011-04-01 00:00:00.000 Caucasian/White NULL Baptist
您可以看到 Averitte 和 Bass 个人资料名称都有一条种族、民族、宗教为 NULL 的记录。如何消除这些行（第 2 行和第 4 行）？
这是我当前的查询：
select distinct
gp.group_profile_id,
gp.profile_name,
gp.license_number,
gp.is_accepting,
case when gp.is_accepting = 1 then 'Yes'
when gp.is_accepting = 0 then 'No '
end as is_accepting_placement,
mo.profile_name as managing_office,
regions.[region_description] as region,
pv.vendor_name,
pv.id as vendor_id,
at.description as applicant_type,
dbo.GetGroupAddress(gp.group_profile_id, null, 0) as [Office Address],
gsv.status_description,
ri.[description] as race,
ethnicity.description as ethnicity_desc,
religion.description as religion
from group_profile gp With (NoLock)
--Office Information
inner join group_profile_type gpt With (NoLock) on gp.group_profile_type_id = gpt.group_profile_type_id and
gpt.type_code = 'FOSTERHOME' and gp.agency_id = @agency_id and gp.is_deleted = 0
inner join group_profile mo With (NoLock) on gp.managing_office_id = mo.group_profile_id
left outer join payor_vendor pv With (NoLock) on gp.payor_vendor_id = pv.payor_vendor_id
left outer join applicant_type at With (NoLock) on gp.applicant_type_id = at.applicant_type_id and at.is_foster_home = 1
inner join group_status_view gsv With (NoLock) on gp.group_profile_id = gsv.group_profile_id and gsv.status_value = 'OPEN' and gsv.effective_date =
(Select max(b.effective_date) from group_status_view b With (NoLock)
where gp.group_profile_id = b.group_profile_id)
left outer join regions With (NoLock) on isnull(mo.regions_id, gp.regions_id) = regions.regions_id
left join enrollment en on en.group_profile_id = gp.group_profile_id
join event_log el on el.event_log_id = en.event_log_id
left join people client on client.people_id = el.people_id
left join race With (NoLock) on el.people_id = race.people_id
left join group_profile_race gpr with (nolock) on gpr.race_info_id = race.race_info_id
left join race_info ri with (nolock) on ri.race_info_id = gpr.race_info_id
left join ethnicity With(NoLock) On client.ethnicity = ethnicity.ethnicity_id
left join religion on client.religion = religion.religion_id
