• left join的多重串联与groupby


    有三张表或组合查询,f1,f2,f3,其中,f1分别与f2,f3是一对多关系,f1一条记录可能对应f2或f3中0条或多条记录

    要创建一个查询,以f1为基准,即f1中有多少条记录,结果也就返回对应数量的记录,并整合f2,f3中的相应信息

    此时需要创建两个left join 串接并加上group by如:

    有三张表或组合查询,f1,f2,f3,其中,f1分别与f2,f3是一对多关系,f1一条记录可能对应f2或f3中0条或多条记录 

    要创建一个查询,以f1为基准,即f1中有多少条记录,结果也就返回对应数量的记录,并整合f2,f3中的相应信息 

    此时需要创建两个left join 串接并加上group by如: 

    select f1.x,f1.y,max(f2.b),wmsys.wm_concat(f3.c)

    from

    (.........

    ) f1

    left join

    (........

    ) f2

    on f1.z=f2.k

    left join

    (........

    ) f3

    on f1.z=f3.c

    group by f1.x,f1.y

    实例

    select f1.pro_uuid,f1.程序类型,f1.程序名,f1.过渡名,f1.航线类型,f1.航线限定1,f1.航线限定2, f1.机型限制

    ,wmsys.wm_concat(nvl2(f2.page,f1.ad||'-'||f2.page,null)) 航图, wmsys.wm_concat(f2.nav_source) 导航源

    ,wmsys.wm_concat(distinct nvl2(f3.rrwd,'RW'||f3.rrwd,null)) 跑道

    from

    (

    select d.procedure_uuid pro_uuid,a.designator ad,

    decode(d.PRO_TYPE,'SID','离场','STAR','进场','IAP','进近',PRO_TYPE) 程序类型,

    d.PRO_NAME 程序名,

    d.TRANS_IDEN 过渡名,

    d.route_type||' '||(select name from TERMPRO_RULE_ROUTE_TYPE where protype=d.pro_type and routetype=d.route_type) 航线类型,

    d.qulifier_1||' '||(select QUALIFIERNAME from TERMPRO_RULE_ROUTE_QUALIFIER where QUALIFIER=d.qulifier_1 and ONE_OR_TWO=1) 航线限定1,

    d.qulifier_2||' '||(select QUALIFIERNAME from TERMPRO_RULE_ROUTE_QUALIFIER where QUALIFIER=d.qulifier_2 and ONE_OR_TWO=2) 航线限定2,

    decode(acft_cat,'P',null,(select name from RULE_ACFT_CAT where CODE_ACFT_CAT= d.acft_cat)) 机型限制

    from TERMINAL_PROCEDURE_TS d,airport_heliport_ts a

    where d.airport_heliport_uuid='4a4ea52d-69be-48e4-baa1-321ee6d023d7'

    and d.airport_heliport_uuid=a.airport_heliport_uuid

    and vernumber(a.eff_version_id)<=201799 and vernumber(a.out_version_id)>201799 and d.interpretation='BASELINE'

    and vernumber(d.eff_version_id)<=201799 and vernumber(d.out_version_id)>201799 and d.interpretation='BASELINE'

    ) f1

    left join

    (

    select pc.procedure_uuid pro_uuid, c.page_number page, tc.type_name nav_source 

    from terminal_chart_ts c, termpro_chart_ts pc, terminal_chart_type tc

    where pc.chart_uuid=c.terminal_chart_uuid

    and c.sub_chart_type_id=tc.chart_type_id

    and vernumber(c.eff_version_id)<=201799 and vernumber(c.out_version_id)>201799 and c.interpretation='BASELINE'

    and vernumber(pc.eff_version_id)<=201799 and vernumber(pc.out_version_id)>201799 and pc.interpretation='BASELINE'

    ) f2

    on f1.pro_uuid=f2.pro_uuid

    left join

    (

    select pw.procedure_uuid pro_uuid, rd.designator rrwd

    from TERMPRO_RWYDRC_TS pw, runway_direction_ts rd

    where pw.runway_direction_uuid=rd.runway_direction_uuid

    and vernumber(pw.eff_version_id)<=201799 and vernumber(pw.out_version_id)>201799 and pw.interpretation='BASELINE'

    and vernumber(rd.eff_version_id)<=201799 and vernumber(rd.out_version_id)>201799 and rd.interpretation='BASELINE'

    ) f3

    on f1.pro_uuid=f3.pro_uuid

    group by f1.pro_uuid,f1.程序类型,f1.程序名,f1.过渡名,f1.航线类型,f1.航线限定1,f1.航线限定2, f1.机型限制

    order by decode(f1.程序类型,'离场',1,'进场',2,'进近',3),f1.程序名,f1.过渡名

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  • 原文地址:https://www.cnblogs.com/mol1995/p/7852137.html
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