Oracle 12C SQL 聚合查詢邏輯

Question

我需要幫助編寫 SQL 查詢以用於以下混合聚合場景：考慮下面的 Emp Table。 需要按經理匯總員工記錄。

聚合邏輯：需要經理下的最高評級。 例如。 對於經理 10，評級應該是超級，對於 30，好

對於評級最低的 emp，需要 EmpDesig 和 Dob。 Sal 和 Bonus 應該由 Sum() 聚合。

   Mgr Emp Rating  EmpSal EmpDesig Bonus     Dob
   10  11   Avg      1000   JE        50   Jan-85
   10  12   Good     1500   SE        30   Mar-85
   10  12   Super    2000   ASE       60   Mar-84
   20  21   Good     1000   SE        40   Apr-85
   20  22   Avg      1000   AST       45   Dec-86
   30  31   Good     500    SE        80   Oct-85
   30  32   Good     1000   ASE       70   Jan-87
   30  33   Avg      1500   ASC       90   Nov-85
   30  34   Avg      500    JE       20    Jan-89

所以上述數據集的 Output 應該是

   Mgr Rating  EmpSal EmpDesig Bonus     Dob
   10   Super    4500   JE       140   Jan-85
   20   Good     2000   AST      85    Dec-86
   30   Good     3500   JE       260   Jan-89

       Create table emp(MgrID number, EmpID number, varchar2(30),EmpSal number, EmpDesig 
      varchar2(30),
      Bonus number,    Dob varchar2(30));
      insert into emp values (10,  11,   'Avg',      1000,   'JE',        50,   'Jan-85');
      insert into emp values (10,  12,   'Good',     1500,   'SE',        30,   'Mar-85');
      insert into emp values (10,  12,   'Super',    2000,   'ASE',       60,   'Mar-84');
      insert into emp values (20,  21,   'Good',     1000,   'SE',        40,   'Apr-85');
      insert into emp values (20,  22,   'Avg',      1000,   'AST',       45,   'Dec-86');
      insert into emp values (30,  31,   'Good',     500,   'SE',        80,   'Oct-85');
      insert into emp values (30,  32,   'Good',    1000,   'ASE',       70,   'Jan-87');
      insert into emp values (30,  33,   'Avg',      1500,   'ASC',       90,   'Nov-85');
      insert into emp values (30,  34,   'Avg',      500,   'ASC',       90,   'Jan-89');

我嘗試使用以下查詢構建邏輯，但不能。

   Select mgr, 
    max(rating) over (partition by mgr order by case Rating when 'Super' then 1 when 'Good' then 2 
    when 'Avg' then 3 end) rating,
    row_number () over (partition by mgr order by case Rating when 'Super' then 1 when 'Good' then 2 
    when 'Avg' then 3 end) rating_rnk,
    sum(empSal),
    sum(bonus),
    max(empdesig) over (partition by mgr order by case Rating when 'Super' then 3 when 'Good' then 2 
    when 'Avg' then 1 end) empdesig,
    row_number () over (partition by mgr order by case Rating when 'Super' then 3 when 'Good' then 2 
    when 'Avg' then 1 end) empdesig_rnk,

    max(dob) over (partition by mgr order by case Rating when 'Super' then 3 when 'Good' then 2 when 
    'Avg' then 1 end) dob,
     row_number () over (partition by mgr order by case Rating when 'Super' then 3 when 'Good' then 
     2 when 'Avg' then 1 end) dob_rnk
    from 
    emp
    group by mgr

Answer 1

這是條件聚合。 我認為關鍵是要列舉收視率：

SELECT mgrid,
    (
        CASE MIN(rating_order)
            WHEN 1   THEN 'Super'
            WHEN 2   THEN 'Good'
            WHEN 3   THEN 'Avg'
        END
    ) AS max_rating,
    MAX(empdesig) KEEP (dense_rank first order by rating_order desc, empid) AS empdesig,
    MAX(dob) KEEP (dense_rank first order by rating_order desc, empid) AS dob,
    SUM(empsal) AS sal, 
    SUM(bonus)
FROM (SELECT e.*, 
         (
             CASE rating
                 WHEN 'Super' THEN 1
                 WHEN 'Good' THEN 2
                 WHEN 'Avg' THEN 3 end ) as rating_order
             FROM emp e
         ) e GROUP BY mgrid;