Oracle SQL如何用更少的代码编写此Join？

Question

Hello Oracle experts I have a question on how to join two tables correctly.

My first table describes an leave category, the minimum years of service time required for new max vacation leave rollover amount and the max rollover numbers.

PTRLVAC_LCAT_CODE   PTRLVAC_YEAR    PTRLVAC_ROLL_MAX_HRS
C1                  0               80                  
C1                  2               88
C1                  5               128
P3                  0               120
P3                  2               128
P3                  5               168

The next table details the employee id, hire date, and leave category

PEBEMPL_PIDM    PEBEMPL_HIRE_DATE   PEBEMPL_LCAT_CODE  
1234            01/09/2017          P3
3214            02/01/2014          C1

The join that I have right now relies on a CTE and I'm not sure if it's the easiest solution. **I've included the tables here as CTEs

with ptrlvac as(
    select 'C1' ptrlvac_lcat_code
          ,0 ptrlvac_year
          ,80 ptrlvac_roll_max_hrs
    from dual union all
    select 'C1', 2, 88 from dual union all
    select 'C1', 5, 128 from dual union all
    select 'P3', 0, 120 from dual union all
    select 'P3', 5, 128 from dual union all
    select 'P3', 2, 168 from dual
    ) , pebempl as(
    select 1234 pebempl_pidm
          ,to_date('09-JAN-2017', 'DD-MON-YYYY') pebempl_hire_date
          ,'P3' pebempl_lcat_code
    from dual
    UNION ALL
    select 3214, to_date('01-FEB-2014','DD-MON-YYYY'), 'C1' from dual
) ,leave as(
    select a.ptrlvac_lcat_code
          ,a.ptrlvac_year
          ,a.ptrlvac_roll_max_hrs
          ,row_number()
              over(partition by a.ptrlvac_lcat_code
                   order by a.ptrlvac_year) rn
    from ptrlvac a
    )
,leave_rules as(
    select a.ptrlvac_lcat_code
          ,a.ptrlvac_year year_start
          ,nvl(b.ptrlvac_year, 100)-1 year_end
          ,a.ptrlvac_roll_max_hrs
    from leave a
         left join leave b
         on  a.ptrlvac_lcat_code = b.ptrlvac_lcat_code
         and a.rn = b.rn - 1
    )
select distinct pebempl_pidm
          ,pebempl_hire_date
          ,floor(months_between(to_date(:seldate, 'DD-MON-YYYY'), pebempl_hire_date) / 12)  as service_years
          ,pebempl_lcat_code as lcat
          ,b.ptrlvac_roll_max_hrs
    from pebempl a
         inner join leave_rules b
         on a.pebempl_lcat_code = b.ptrlvac_lcat_code
         and floor(months_between(to_date(:seldate, 'DD-MON-YYYY'), pebempl_hire_date) / 12) between b.year_start and b.year_end

Any help to save some keystrokes would be greatly appreciated.

Thanks in advance.

Answer 1

I'm not sure if this does what you want:

select
t2.PEBEMPL_PIDM,
t1.PTRLVAC_ROLL_MAX_HRS
from test1 t1, test2 t2
where
t1.PTRLVAC_LCAT_CODE = t2.PEBEMPL_LCAT_CODE and
t1.PTRLVAC_YEAR = 
(select max(t1s.PTRLVAC_YEAR) from test1 t1s
where t1s.PTRLVAC_LCAT_CODE = t2.PEBEMPL_LCAT_CODE
and (sysdate-PEBEMPL_HIRE_DATE)/365 >= t1s.PTRLVAC_YEAR);

Here are the results I got based on your test data:

PEBEMPL_PIDM PTRLVAC_ROLL_MAX_HRS                                               
------------ --------------------                                               
        3214                   88                                               
        1234                  120                                               

Bobby

Answer 2

Had this thought over lunch, further reducing @BobbyDurret's answer:

select
t2.PEBEMPL_PIDM,
max(t1.PTRLVAC_ROLL_MAX_HRS)
from ptrlvac t1, pebempl t2
where
t1.PTRLVAC_LCAT_CODE = t2.PEBEMPL_LCAT_CODE and
(sysdate-PEBEMPL_HIRE_DATE)/365 >= t1.PTRLVAC_YEAR
group by t2.PEBEMPL_PIDM

Assumes the Max_Hrs always increases for more years of service.

Answer 3

Instead of using row_number and filtering in a separate CTE, use lead:

with leave_rules as
(
    select a.ptrlvac_lcat_code
          ,a.ptrlvac_year as year_start
          ,a.ptrlvac_roll_max_hrs
          ,lead(ptrlvac_year,1,10000) over (partition by ptrlvac_lcat_code
                                 order by ptrlvac_year)
          as year_end
    from ptrlvac a
)
select distinct pebempl_pidm
          ,pebempl_hire_date
          ,floor(months_between(sysdate, pebempl_hire_date) / 12)  as service_years
          ,pebempl_lcat_code as lcat
          ,b.ptrlvac_roll_max_hrs
    from pebempl a
         inner join leave_rules b
         on a.pebempl_lcat_code = b.ptrlvac_lcat_code
         and floor(months_between(sysdate, pebempl_hire_date) / 12) between year_start and year_end

Combines your 2 CTE's to compute "leave_rules" into 1. I just put sysdate for the date variable so I could test easily - you probably want to use the bind variables as you originally had.