如何在 SQL 查询中填充 Min 和 Max 之间的所有值的范围？

Question

我有以下看法：

select v.* from myview v;

PeriodID | StartMonth | EndMonth
102      |          1 |        4
103      |          3 |        7
104      |          4 |        11

我需要将此视图与此查询（另一个视图）混合。

select q.* from query q;

Somevalue| AnotherValue| PeriodId
   'abc' |         546 |      102
   'xyz' |         147 |      103
   'bnm' |         652 |      104

我需要：

Somevalue| AnotherValue| PeriodId | Month
   'abc' |         546 |      102 |     1
   'abc' |         546 |      102 |     2
   'abc' |         546 |      102 |     3
   'abc' |         546 |      102 |     4
   'xyz' |         147 |      103 |     3
   'xyz' |         147 |      103 |     4
   'xyz' |         147 |      103 |     5
   'xyz' |         147 |      103 |     6
   'xyz' |         147 |      103 |     7

如果我可以从startmonth to endmonth 获得一个集合并与 q 一起加入它，也许我可以得到我需要的。

来自：

PeriodID | StartMonth | EndMonth
102      |          1 |        4
103      |          3 |        7
104      |          4 |        11

收件人：

PeriodID |      Month
102      |          1
102      |          2
102      |          3
102      |          4

Answer 1

我更改了名称以使查询更清晰

myview --> periods_table

query --> values_table

SELECT vl.*
      ,pr.month
  FROM (SELECT periodid AS periodid 
              ,LEVEL    AS month
          FROM periods_table t
         WHERE LEVEL >= t.startmonth
         GROUP BY periodid, LEVEL
        CONNECT BY LEVEL <= t.endmonth) pr
      , values_table vl
 WHERE pr.periodid = vl.periodid
 ORDER BY pr.periodid, pr.month

Answer 2

with t as (select 1 monthid from dual union all select 2 from dual
           ...)
select q.somevalue, q.anothervalue, m.periodid, t.monthid
from t 
join myview m on t.monthid between m.startmonth and m.endmonth
join q on q.periodid = m.periodid

你可以用数字和join 将它构建到你的表中。

Answer 3

给出相同结果的两种解决方案：

SQL Fiddle

Oracle 11g R2 架构设置：

CREATE TABLE myview ( PeriodID, StartMonth, EndMonth ) AS
          SELECT 102, 1, 4 FROM DUAL
UNION ALL SELECT 103, 3, 7 FROM DUAL
UNION ALL SELECT 104, 4, 11 FROM DUAL;

CREATE TABLE query ( Somevalue, AnotherValue, PeriodId ) AS
          SELECT 'abc', 546, 102 FROM DUAL
UNION ALL SELECT 'xyz', 147, 103 FROM DUAL
UNION ALL SELECT 'bnm', 652, 104 FROM DUAL;

查询 1 - 使用递归子查询分解：

WITH Periods ( PeriodID, Month, EndMonth ) AS (
  SELECT PeriodID, StartMonth, EndMonth
  FROM   myview
  WHERE  StartMonth <= EndMonth
  UNION ALL
  SELECT PeriodID, Month + 1, EndMonth
  FROM   Periods
  WHERE  Month < EndMonth
)
SELECT p.PeriodID,
       q.SomeValue,
       q.AnotherValue,
       p.Month
FROM   Periods p
       INNER JOIN
       Query q
       ON ( p.PeriodID = q.PeriodID )
ORDER BY PeriodID, Month

查询 2 - 使用分层查询：

WITH Periods ( PeriodID, Month ) AS (
  SELECT m.PeriodID,
         t.COLUMN_VALUE
  FROM   myview m,
         TABLE(
           CAST(
             MULTISET(
               SELECT m.StartMonth + LEVEL - 1
               FROM   DUAL
               CONNECT BY m.StartMonth + LEVEL - 1 <= m.EndMonth
             )
             AS SYS.ODCINUMBERLIST
           )
         ) t
)
SELECT p.PeriodID,
       q.SomeValue,
       q.AnotherValue,
       p.Month
FROM   Periods p
       INNER JOIN
       Query q
       ON ( p.PeriodID = q.PeriodID )

Results：

| PERIODID | SOMEVALUE | ANOTHERVALUE | MONTH |
|----------|-----------|--------------|-------|
|      102 |       abc |          546 |     1 |
|      102 |       abc |          546 |     2 |
|      102 |       abc |          546 |     3 |
|      102 |       abc |          546 |     4 |
|      103 |       xyz |          147 |     3 |
|      103 |       xyz |          147 |     4 |
|      103 |       xyz |          147 |     5 |
|      103 |       xyz |          147 |     6 |
|      103 |       xyz |          147 |     7 |
|      104 |       bnm |          652 |     4 |
|      104 |       bnm |          652 |     5 |
|      104 |       bnm |          652 |     6 |
|      104 |       bnm |          652 |     7 |
|      104 |       bnm |          652 |     8 |
|      104 |       bnm |          652 |     9 |
|      104 |       bnm |          652 |    10 |
|      104 |       bnm |          652 |    11 |

Answer 4

这是您问题的答案。

DECLARE @TABLE1 TABLE
(
  PERIODID INT,
  STARTMONTH INT,
  ENDMONTH INT
)

DECLARE @TABLE2 TABLE
(
  SOMEVALUE VARCHAR(20),
  ANOTHERVALUE INT,
  PERIODID INT
)

INSERT INTO @TABLE1 VALUES (102,1,3)
INSERT INTO @TABLE1 VALUES (103,3,7)
INSERT INTO @TABLE2 VALUES ('ABC',123,102)
INSERT INTO @TABLE2 VALUES ('BCD',234,103)

;WITH cte
 AS (SELECT PERIODID, STARTMONTH [MONTH],ENDMONTH
     FROM   @TABLE1 
     UNION ALL
     SELECT PERIODID, [MONTH] + 1,ENDMONTH
     FROM   cte
     WHERE  [MONTH] < ENDMONTH)

SELECT T2.SOMEVALUE,T2.ANOTHERVALUE, CTE.PERIODID,CTE.[MONTH] FROM CTE 
INNER JOIN @TABLE2 T2 ON CTE.PERIODID =  T2.PERIODID
ORDER BY CTE.PERIODID,CTE.MONTH

检查此SQLFiddle 并尝试根据您的情况进行调整。它肯定会奏效。

快乐编码