根据已加入 table 中的最新日期获取结果

Question

我有 2 个表 tbl_job & tbl_appointment

我想获取所有以 job_refrence = '1%' 开头的活动作业以及最新的活动 appointment.created_when 和 appointment_type 与之关联的 appointment.created_when

一个工作可以有多个约会
如果与该工作相关的所有约会 deleted_flag = 1 那么结果集应该 return tbl_job.created-when 作为 latest_appointment_date

CREATE TABLE [dbo].[tbl_job]
(
    
    [job_id] UNIQUEIDENTIFIER NOT NULL,
    [account_id] INT NOT NULL,
    [description] NVARCHAR(1024) NULL, 
    [deleted_flag] BIT NOT NULL,
    [created_when] DATETIME2 (6) NOT NULL,
    [job_reference] NVARCHAR(15) NOT NULL
)

CREATE TABLE [dbo].[tbl_appointment]
(
    
    [appointment_id] UNIQUEIDENTIFIER NOT NULL,
    [job_id] UNIQUEIDENTIFIER NOT NULL,
    [deleted_flag] BIT NOT NULL,
    [appointment_type] NVARCHAR(35) NOT NULL,
    [created_when] DATETIME2 (6) NOT NULL,
    [account_id] INT NULL,
)

insert into dbo.tbl_job (job_id,    account_id, [description],  deleted_flag,   created_when,   job_reference) values
('A29A6381-EF0D-47F6-BFC3-051679E343D0',    1,  'descr1',   0,  '2020-06-12 00:58:17.7221410',  1  )
,('4D8C1B04-9E00-41FA-BDB8-653C26712144',   1,  'descr2',   0,  '2020-06-10 00:58:17.7221410',  12 )
,('F8DC690E-74AB-46F4-90D3-55E032F21C99',   1,  'descr3',   0,  '2020-06-26 00:58:17.7221410',  123 )
,('C5D8AA45-FA45-41A4-877D-5B803C1BE61B',   1,  'descr4',   0,  '2020-06-27 00:58:17.7221410',  76 )

insert into dbo.tbl_appointment(appointment_id, job_id, deleted_flag,   appointment_type,   created_when,   account_id) Values
('9E24451F-5703-414F-ACF1-9304AFBEA8F1',    'A29A6381-EF0D-47F6-BFC3-051679E343D0', 0,  'job1_cat1',    '2020-06-12 00:58:17.7221410',  1)
,('A8121DC1-271E-4BD0-A6AA-D753CF4D310E',   'A29A6381-EF0D-47F6-BFC3-051679E343D0', 0,  'job1_cat2',    '2020-06-14 00:58:17.7221410',  1)
,('61ED5B48-DF95-4FC8-AF1D-1418C6DD9088',   '4D8C1B04-9E00-41FA-BDB8-653C26712144', 0,  'job2_cat1',    '2020-06-15 00:58:17.7221410',  1)
,('0e4fc735-96c3-4cab-8ade-796bae4639d1',   'F8DC690E-74AB-46F4-90D3-55E032F21C99', 1,  'job3_cat1',    '2020-06-28 00:58:17.7221410',  1)

预期结果集

job_id                                  job_reference       latest_appointment_date         appointment_type total_rows
F8DC690E-74AB-46F4-90D3-55E032F21C99    123                 2020-06-26 00:58:17.722141      NULL                3
4D8C1B04-9E00-41FA-BDB8-653C26712144    12                  2020-06-15 00:58:17.722141      job2_cat1           3
A29A6381-EF0D-47F6-BFC3-051679E343D0    1                   2020-06-14 00:58:17.722141      job1_cat2           3

下面的查询有效，但效率不高，因为我们的表中有数百万行。我想用 Left join 或其他方式替换 OUTER apply 以提高效率

    DECLARE @filtered_jobs TABLE
    (
         job_domain_id UNIQUEIDENTIFIER
        ,job_reference NVARCHAR(15)
        ,job_created_when DATETIME2(6)
        ,latest_appointment_date DATETIME2(6)
        ,appointment_type NVARCHAR(35)
        
    );
    declare @account_id int = 1
    declare     @job_reference nvarchar(35) = '1'
    declare     @offset int  = 0
    declare     @limit int = 10
    declare     @is_sort_ascending int = 0


            INSERT INTO @filtered_jobs (job_domain_id, job_reference, job_created_when, latest_appointment_date,appointment_type)
            SELECT   
                    j.job_id
                    ,j.job_reference
                    ,j.created_when
                    ,ap.created_when AS latest_appointment_date
                    ,ap.appointment_type
            FROM    dbo.tbl_job j
                    OUTER APPLY (
                        SELECT TOP (1) ap.appointment_type,ap.created_when,ap.deleted_flag
                        FROM    dbo.tbl_appointment ap 
                        WHERE   ap.job_id = j.job_id AND ap.deleted_flag = 0
                        ORDER BY ap.created_when desc
                    ) ap
            WHERE   j.account_id =  @account_id
                    AND j.job_reference LIKE (@job_reference + '%')
                    AND j.deleted_flag = 0
    

    SELECT 
             fj.job_domain_id
            ,fj.job_reference
            ,ISNULL(fj.latest_appointment_date,fj.job_created_when) AS latest_appointment_date
            ,fj.appointment_type
    FROM    @filtered_jobs fj
    ORDER BY 
            CASE WHEN @is_sort_ascending = 0 THEN ISNULL(fj.latest_appointment_date,fj.job_created_when) END DESC,
            CASE WHEN @is_sort_ascending = 1 THEN ISNULL(fj.latest_appointment_date,fj.job_created_when)  END ASC
            OFFSET @offset ROWS FETCH NEXT @limit ROWS ONLY;

    SELECT  COUNT(1) AS total_records 
    FROM    @filtered_jobs;

Answer 1

您可以使用运行king 函数，但您需要测试它是否更快：

根据您发布的查询，将 insert into @filtered_jobs 替换为以下 2:

    INSERT INTO @filtered_jobs (job_domain_id, job_reference, job_created_when)
    select  j.job_id
            ,j.job_reference
            ,j.created_when
    FROM    dbo.tbl_job j
    WHERE   j.account_id =  @account_id
            AND j.job_reference LIKE (@job_reference + '%')
            AND j.deleted_flag = 0
    
    update f
        set latest_appointment_date=x.latest_appointment_date,
            appointment_type=x.appointment_type
    from @filtered_jobs f
    inner join ( 
        select f.job_domain_id
                ,ap.created_when AS latest_appointment_date
                ,ap.appointment_type as appointment_type
                , rank() over (partition by ap.job_id order by ap.created_when desc) rnk
        from @filtered_jobs f
        inner join dbo.tbl_appointment ap on ap.job_id = f.job_domain_id
        where ap.deleted_flag = 0) x on f.job_domain_id=x.job_domain_id
    where x.rnk=1

确保您在 dbo.tbl_appointment（列 job_id、ap.deleted_flag）上有一个索引，如果此查询最好包括 (created_when、appointment_type) 运行很多。

根据已加入 table 中的最新日期获取结果

Get Results based on the latest date in a Joined table

sql

sql-server

join

sql-server-2016