我希望获得一些帮助来优化此查询以使其更快。
此查询产生一个视图，该视图将显示在网站的表格中。 这个查询很慢，我正在尝试使其更快。
到目前为止，我唯一尝试做的就是减少为表检索的列数。
这是查询：
SELECT TOP (100) PERCENT Id, MAX(BusinessTitle) AS BusinessTitle, MAX(ClientName) AS ClientName, MAX(ClientType) AS Type, MAX(CreatedWhen) AS CreatedWhen, MAX(CASE WHEN C.[CreatedBy] IS NULL
THEN 'Client' ELSE 'Admin' END) AS CreatedBy, CAST(MAX(CASE WHEN C.IsDisabled = 1 THEN 1 ELSE 0 END) AS BIT) AS IsDisabled, MAX(ReferenceSource) AS ReferenceSource, MAX(OtherReferenceSource)
AS OtherReferenceSource, MAX(Address) AS Address,
(SELECT MAX(T.FirstName + ' ' + T.LastName) AS Expr1
FROM dbo.ApplicationUsers AS A INNER JOIN
dbo.Therapists AS T ON A.UserName = MAX(C.ClientName) AND A.Id = T.ApplicationUserId) AS ClientAdmin,
(SELECT MAX(A.Email) AS Expr1
FROM dbo.ApplicationUsers AS A INNER JOIN
dbo.Therapists AS T ON A.UserName = MAX(C.ClientName) AND A.Id = T.ApplicationUserId) AS Email,
(SELECT MAX(Name) AS Expr1
FROM dbo.Cities AS CY
WHERE (Id = MAX(C.CityId))) AS City,
(SELECT COUNT(*) AS Expr1
FROM dbo.Patients AS P
WHERE (ClientId = C.Id)) AS TotalPatientCount,
(SELECT COUNT(*) AS Expr1
FROM dbo.Patients AS P
WHERE (ClientId = C.Id) AND (IsDeleted = 0) AND (IsDisabled = 0)) AS ActivePatientCount,
(SELECT MAX(CreatedWhen) AS Expr1
FROM dbo.Patients AS P
WHERE (ClientId = C.Id)) AS LastPatientAddition,
(SELECT COUNT(*) AS Expr1
FROM dbo.Treatments AS T
WHERE (ClientId = C.Id)) AS TotalTreatmentCount,
(SELECT MAX(CreatedWhen) AS Expr1
FROM dbo.Treatments AS T
WHERE (ClientId = C.Id)) AS LastTreatmentAddition,
(SELECT COUNT(*) AS Expr1
FROM dbo.Therapists AS T
WHERE (ClientId = C.Id)) AS TotalTherapistCount,
(SELECT COUNT(*) AS Expr1
FROM dbo.Therapists AS T INNER JOIN
dbo.ApplicationUsers AS A ON T.ClientId = C.Id AND T.ApplicationUserId = A.Id
WHERE (A.IsDeleted = 0) AND (A.IsDisabled = 0)) AS ActiveTherapistCount,
(SELECT MAX(A.CreatedWhen) AS Expr1
FROM dbo.Therapists AS T INNER JOIN
dbo.ApplicationUsers AS A ON T.ClientId = C.Id AND T.ApplicationUserId = A.Id) AS LastTherapistAddition,
(SELECT MAX(A.LastLoginDate) AS Expr1
FROM dbo.Therapists AS T INNER JOIN
dbo.ApplicationUsers AS A ON T.ClientId = C.Id AND T.ApplicationUserId = A.Id
WHERE (A.LastLoginDate IS NOT NULL)) AS TherapistLastLoginDate, CAST((CASE WHEN
((SELECT COUNT(S.[Id])
FROM [dbo].[ClientSubscriptions] AS S
WHERE ((S.[ClientId] = C.[Id]) AND (S.[IsDeleted] = 0) AND ((S.[SubscriptionEnd] IS NULL) OR
(S.[SubscriptionEnd] > GETDATE())))) > 0) THEN 1 ELSE 0 END) AS BIT) AS HasActiveSubscription,
(SELECT MAX(SubscriptionEnd) AS Expr1
FROM dbo.ClientSubscriptions AS S
WHERE (ClientId = C.Id) AND (IsDeleted = 0) AND (SubscriptionEnd IS NULL OR
SubscriptionEnd > GETDATE())) AS LastValidSubscriptionEnd, CAST((CASE WHEN
((SELECT COUNT(S.[Id])
FROM [dbo].[ClientSubscriptions] AS S
WHERE ((S.[ClientId] = C.[Id]) AND (S.[IsDeleted] = 0) AND ((S.[SubscriptionEnd] IS NULL) OR
(S.[SubscriptionEnd] > GETDATE())) AND (S.[Id] <>
(SELECT MIN(S2.[Id])
FROM [dbo].[ClientSubscriptions] AS S2
WHERE ((S2.[ClientId] = C.[Id]) AND (S2.[IsDeleted] = 0)))))) > 0) THEN 1 ELSE 0 END) AS BIT) AS IsPayingCustomer, COALESCE
((SELECT MAX(MonthlyPrice) AS Expr1
FROM dbo.ClientSubscriptions AS S
WHERE (ClientId = C.Id) AND (IsDeleted = 0) AND (SubscriptionEnd IS NULL OR
SubscriptionEnd > GETDATE()) AND (MonthlyPrice > 0)), 0.00) AS ActiveSubscriptionMonthlyPrice, MAX(ClientStatus) AS Status, MAX(Phone1) AS Phone, MAX(Phone2) AS Phone2,
(SELECT Code
FROM dbo.DiscountCoupons AS DC
WHERE (Code =
(SELECT TOP (1) DiscountCouponCode
FROM dbo.ClientPayments AS CP
WHERE (ClientId = C.Id)
ORDER BY Id))) AS DiscountCouponCode,
(SELECT IssuedTo
FROM dbo.DiscountCoupons AS DC
WHERE (Code =
(SELECT TOP (1) DiscountCouponCode
FROM dbo.ClientPayments AS CP
WHERE (ClientId = C.Id)
ORDER BY Id))) AS DiscountCouponIssuedTo,
(SELECT ClientDiscount
FROM dbo.DiscountCoupons AS DC
WHERE (Code =
(SELECT TOP (1) DiscountCouponCode
FROM dbo.ClientPayments AS CP
WHERE (ClientId = C.Id)
ORDER BY Id))) AS DiscountCouponClientDiscount, COALESCE
((SELECT COUNT(Id) AS Expr1
FROM dbo.ClientFiles AS F
WHERE (ClientId = C.Id)), 0) AS TotalFilesCount, COALESCE
((SELECT SUM(FileSize) AS Expr1
FROM dbo.ClientFiles AS F
WHERE (ClientId = C.Id)), 0) / 1048576.0 AS TotalFilesSize, CAST(MAX(CASE WHEN C.CrmEnded = 1 THEN 1 ELSE 0 END) AS BIT) AS CrmEnded, MAX(CrmStatus) AS CrmStatus, MAX(CrmUnuseReason)
AS CrmUnuseReason,
(SELECT COUNT(1) AS Expr1
FROM dbo.Tipulog_Crm_Calls_new AS CC
WHERE (Cust_id = C.Id)) AS CrmCallCount
FROM dbo.Clients AS C
WHERE (IsDeleted = 0)
GROUP BY Id
答案 0 :(得分：0)
这是一个很不完整的答案，但是您询问如何一次而不是多次在多个子查询中引用一个表。
这是一个示例，您将如何替换所有这些子查询到“患者与治疗”表以及“城市”表中。您真的需要了解联接。
FROM dbo.Clients AS C
join dbo.Cities on Cities.ID=c.CityID
left join (
SELECT ClientId,
COUNT(*) AS TotalPatientCount,
sum(case when IsDeleted = 0 AND IsDisabled = 0 then 1 else 0 end) AS ActivePatientCount,
MAX(CreatedWhen) AS LastPatientAddition
FROM dbo.Patients
GROUP BY ClientId
) Patients on Patients.ClientId = C.Id
left join (
SELECT ClientId,
COUNT(*) AS TotalTreatmentCount,
MAX(CreatedWhen) AS LastTreatmentAddition
FROM dbo.Treatments
GROUP BY ClientId
) Treatments on Treatments.ClientID = C.Id
然后，您的列列表将替换患者和城市的子查询，如下所示：
Cities.Name AS City,
Patients.TotalPatientCount,
Patients.ActivePatientCount,
Patients.LastPatientAddition,
Treatments.TotalTreatmentCount,
Treatments.LastTreatmentAddition,
那至少应该给你一个主意。
答案 1 :(得分：0)
我将添加第二个答案，即完整的sql。当然，这没有经过测试，因为我们无法访问您的数据，但是我认为您应该可以自己调试它。这段代码中有许多指针应向您展示如何操作。
最基本的是取出所有相关查询并将它们作为子查询。这样做的唯一原因是您使用的所有最大/最小-我视这些数据为依据，认为它们不是必需的，那么您应该将它们取出并直接连接到表中。所有子查询都是左联接-如果可以的话，再次使它们成为普通联接。
还按ID排除了外部组，因为99％的人都不需要这样做，前100％的人也是如此。
SELECT BusinessTitle, ClientName, ClientType AS Type, CreatedWhen,
CASE WHEN C.[CreatedBy] IS NULL THEN 'Client' ELSE 'Admin' END) AS CreatedBy,
CAST(CASE WHEN C.IsDisabled = 1 THEN 1 ELSE 0 END AS BIT) AS IsDisabled,
ReferenceSource, OtherReferenceSource, Address,
ApplicationByName.FullName AS ClientAdmin,
ApplicationByName.Email AS Email,
Cities.Name AS City,
Patients.TotalPatientCount,
Patients.ActivePatientCount,
Patients.LastPatientAddition,
Treatments.TotalTreatmentCount,
Treatments.LastTreatmentAddition,
Therapists.TotalTherapistCount,
Therapists.ActiveTherapistCount,
Therapists.LastTherapistAddition,
Therapists.TherapistLastLoginDate
CAST(CASE WHEN Subscriptions.SubscriptionCount>0 then 1 else 0 end as BIT) as HasActiveSubscription,
Subscriptions.LastValidSubscriptionEnd
CAST(Subscriptions.IsPayingCustomer AS BIT) AS IsPayingCustomer,
COALESCE(ActiveSubscriptionMonthlyPrice,0) as ActiveSubscriptionMonthlyPrice
ClientStatus AS Status, Phone1 AS Phone, Phone2 AS Phone2,
ClientPayments.DiscountCouponCode,
DiscountCoupons.IssuedTo AS DiscountCouponIssuedTo,
DiscountCoupons.ClientDiscount AS DiscountCouponClientDiscount,
COALESCE(ClientFiles.TotalFilesCount,0) AS TotalFilesCount,
COALESCE(ClientFiles.TotalFilesSize,0) AS TotalFilesSize,
CAST((CASE WHEN C.CrmEnded = 1 THEN 1 ELSE 0 END) AS BIT) AS CrmEnded,
CrmStatus, CrmUnuseReason,
Crm_Calls.CrmCallCount
FROM dbo.Clients AS C
left join (
select A.UserName,
max(T.FirstName + ' ' + T.LastName) as FullName,
max(A.Email) as Email
from dbo.ApplicationUsers A
join dbo.Therapists T on T.ApplicationUserId=A.Id
group by A.Username
) ApplicationByName on ApplicationByName.UserName=C.ClientName
join dbo.Cities on Cities.ID=c.CityID
left join (
SELECT ClientId,
COUNT(*) AS TotalPatientCount,
sum(case when IsDeleted = 0 AND IsDisabled = 0 then 1 else 0 end) AS ActivePatientCount,
MAX(CreatedWhen) AS LastPatientAddition
FROM dbo.Patients
GROUP BY ClientId
) Patients on Patients.ClientId = C.Id
left join (
SELECT ClientId,
COUNT(*) AS TotalTreatmentCount,
MAX(CreatedWhen) AS LastTreatmentAddition
FROM dbo.Treatments
GROUP BY ClientId
) Treatments on Treatments.ClientID = C.Id
left join (
select T.ClientId,
count(distinct T.Id) as TotalTherapistCount,
sum(case when A.IsDeleted = 0 AND A.IsDisabled = 0 then 1 else 0 end) as ActiveTherapistCount,
max(A.CreatedWhen) as LastTherapistAddition,
max(A.LastLoginDate) as TherapistLastLoginDate
from Therapists T
left join dbo.ApplicationUsers A on A.Id=T.ApplicationUserId
group by T.ClientId
) Therapists on Therapists.ClientID = C.Id
left join (
SELECT S.ClientId,
count(*) as SubscriptionCount,
MAX(SubscriptionEnd) as LastValidSubscriptionEnd,
MAX(case when MinSub.Id!=S.ID then 1 else 0 end as IsPayingCustomer,
max(case when MonthlyPrice>0 then 0 end) as ActiveSubscriptionMonthlyPrice
FROM dbo.ClientSubscriptions S
join (
select ClientId, min(Id) as Id
from dbo.ClientSubscriptions
where IsDeleted=0
group by ClientId
) MinSub on MinSub.ClientId=ClientSubscriptions.ClientId
where IsDeleted=0 and (SubscriptionEnd is null or SubscriptionEnd>getdate())
group by ClientId
) Subscriptions on Subscriptions.ClientId=C.Id
left join (
select ClientId,
DiscountCouponCode,
row_number() over(partition by ClientId, order by Id) rn
from dbo.ClientPayments
) ClientPayments on ClientPayments.ClientId=C.ID and rn=1
left join dbo.DiscountCoupons on DiscountCoupons.Code=ClientPayments.DiscountCouponCode
left join (
select ClientId,
count(*) as TotalFilesCount,
sum(FileSize)/1048576.0 as TotalFilesSize
from dbo.ClientFiles
group by ClientId
) ClientFiles on ClientFiles.ClientId=Client.Id
left join (
SELECT Cust_id, COUNT(1) AS CrmCallCount
FROM dbo.Tipulog_Crm_Calls_new
group by Cust_id
) Crm_Calls on Crm_Calls.Cust_id=C.Id
WHERE C.IsDeleted = 0