加入开始日期的基础上表和结束日期

Question

子表

Start Date End Date Name Cd Parent1 Parent2 
    1/1/1900 3/6/2016 X  X A   B 
    3/6/2016 12/31/4712 X-1 X A   B 

父表1

 Start Date  End Date Name Cd Grand Parent 
    1/1/1900  2/5/2015 A  A AA 
    2/5/2015  6/8/2016 A-1 A AA 
    6/8/2016  1/1/4712 A-2 A AA 

祖父母表

 Start Date  End Date Name Cd 
    1/1/1900  2/7/2015 AA  AA 
    2/7/2015  1/1/4712 AA-1 AA 

父表2

 Start Date  End Date Name Cd 
    1 1/1/1900 1/1/2012 B  B 
    2 1/1/2012 3/6/2016 B-1  B 

我要像下面的基础上开始最终结果的东西/结束日期

 Start Date C P1 GP P2 
    1/1/1900 X A AA B 
    1/1/2012 X A AA B-1 
    2/5/2015 X A-1 AA B-1 
    2/7/2015 X A-1 AA-1 B-1 
    3/6/2016 X-1 A-1 AA-1 B-2 
    6/8/2016 X-1 A-2 AA-1 B-2 
    1/1/2017 X-1 A-2 AA-1 B-3 
    2/2/2017 X-1 A-2 AA-2 B-3 

有人可以帮我换上述方案编写SQL TIA

Answer 1

这里是一个解决方案，根据提供的样本数据。我给表格打电话：childtable，parent1，parent2，gparent。

我创建了一个名为的WITH子句DATE_RANGE以获取所需日期列表。你也可以在子查询中做到这一点。

WITH DATE_RANGE AS ( 
      select distinct start_date FROM childtable 
      union 
      select distinct start_date from parent1 
      union 
      select distinct start_date from gparent 
      union 
      select distinct start_date from parent2 
    ) 
     SELECT 
     D.START_DATE, 
     C.START_DATE, 
     C.NAME C, 
     P1.NAME P1, 
     GP.NAME GP, 
     P2.NAME P2 
     FROM 
     DATE_RANGE D 
     JOIN CHILDTABLE C ON C.END_DATE > D.START_DATE 
     JOIN PARENT1 P1 ON P1.CD = C.PARENT1 AND P1.END_DATE > D.START_DATE 
     JOIN GPARENT GP ON GP.CD = P1.GPARENT AND GP.END_DATE > D.START_DATE 
     JOIN PARENT2 P2 ON P2.CD = C.PARENT2 AND P2.END_DATE > D.START_DATE 
     WHERE 
     C.START_DATE = (SELECT MIN(START_DATE) FROM CHILDTABLE C2 
         WHERE C2.END_DATE > D.START_DATE  ) and 
     P1.START_DATE = (SELECT MIN(START_DATE) FROM PARENT1 P12 
          WHERE P12.END_DATE > D.START_DATE ) and 
     GP.START_DATE = (SELECT MIN(START_DATE) FROM GPARENT GP2 
          WHERE GP2.END_DATE > D.START_DATE ) and 
     P2.START_DATE = (SELECT MIN(START_DATE) FROM PARENT2 P22 
          WHERE P22.END_DATE > D.START_DATE ) 
     ORDER BY D.START_DATE 
     ; 

子查询例如：

SELECT D.START_DATE, C.START_DATE, C.NAME C 
    ,P1.NAME P1 ,GP.NAME GP ,P2.NAME P2 
    FROM 
    (select distinct start_date FROM childtable 
     union 
     select distinct start_date from parent1 
     union 
     select distinct start_date from gparent 
     union 
     select distinct start_date from parent2) D 
    JOIN CHILDTABLE C ON C.END_DATE > D.START_DATE 
    JOIN PARENT1 P1 ON P1.CD = C.PARENT1 AND P1.END_DATE > D.START_DATE 
...