NULL-rijen in TSQL-query elimineren

Mogelijk duplicaat:
   NULL-velden in TSQL verwijderen

I am using SSMS 2008 R2 and am developing a TSQL query. I want just 1 record/profile_name. Because some of these values are NULL, I am currently doing LEFT JOINS on most of the tables. But the problem with the LEFT JOINs is that now I get > 1 record for some profile_names!

Maar als ik dit in INNER JOINs wijzig, worden sommige profielnamen volledig uitgesloten omdat ze NULL-waarden hebben voor deze kolommen. Hoe beperk ik het queryresultaat tot slechts één record/profielnaam, ongeacht NULL-waarden? En als er niet-NULL-waarden zijn, wil ik dat deze de record met niet-NULL-waarden kiest. Hier is de eerste vraag:

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
from  group_profile gp With (NoLock)
    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

Zoals u ziet, zijn de resultaten van de bovenstaande zoekopdracht 1 rij/profielnaam:

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

Maar kijk nu wat er gebeurt als ik 2 LINKSE JOINs en 1 extra kolom toevoeg:

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
from  group_profile gp With (NoLock)
    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 race_info ri with (nolock) on ri.race_info_id = race.race_info_id

De bovenstaande query resulteert in alle dezelfde profile_names, maar sommige met NULL race-waarden:

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

Helaas compliceert het zaken die ik nodig heb om deel te nemen in 2 extra tabellen voor deze ene extra veldwaarde (race). Als ik simpelweg de laatste twee links naar links in INNER JOINs verander, elimineer ik de NULL-rijen hierboven. Maar ik verwijder ook enkele van de profielnamen:

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

Hopelijk heb ik alle details gegeven die je nodig hebt voor deze vraag.