如何避免重疊深度間隔範圍何時使用分組子句

Question

我需要基於沿相同代碼的深度間隔分組來生成彙總表。我嘗試了使用Minimum From_Depth和Meximum To_Depth的簡單group by子句，但它消除了重疊更改。下面是例子：

Create Table #Lithology (
     Hole_ID varchar(10) 
    , mFrom int 
    , mTo int 
    , Strat varchar(10) 
    ,Strand varchar(10) 
) 

insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 0, 2, 'CzD3', 'ALU'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 2, 4, 'CzD3', 'ALU'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 4, 6, 'CzD3', 'SCR'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 6, 8, 'CzD3', 'SCR'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 6, 8, 'CzD3', 'SCR'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 8, 10, 'CzD2', 'CIDW'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 10, 12, 'CzD2', 'CIDW'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 12, 14, 'CzD2', 'CIDO'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 14, 16, 'CzD2', 'CIDW'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 16, 18, 'CzD2', 'CIDW'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 18, 20, 'NAM', 'TNAM'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 20, 22, 'NAM', 'TNAM'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 22, 24, 'NAM', 'SNAM'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 24, 26, 'NAM', 'SNAM'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 26, 28, 'NAM', 'SONAM'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 28, 30, 'NAM', 'SONAM'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 30, 32, 'NAM', 'SNAM'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 32, 34, 'NAM', 'SNAM'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 34, 36, 'NAM', 'NNAM'); 
insert into #Lithology (Hole_ID, mFrom, mTo, Strat, Strand) values ('MD4803', 36, 38, 'NAM', 'NNAM'); 


select Hole_ID 
, min(mFrom) StartDepth 
, max(mTo) EndDepth 
, Strat, Strand 
from #Lithology 
group by Hole_ID, Strat, Strand 
order by MIN(mFrom) 

它返回以下結果，重疊的深度範圍。

Hole_ID StartDepth EndDepth Strat Strand 
MD4803 0   4   CzD3 ALU 
MD4803 4   8   CzD3 SCR 
MD4803 8   18   CzD2 CIDW 
MD4803 12   14   CzD2 CIDO 
MD4803 18   22    NAM TNAM 
MD4803 22   34   NAM SNAM 
MD4803 26   30   NAM SONAM 
MD4803 34   38   NAM NNAM 

預期的結果是，如下面沒有重疊的時間間隔：

Hole_ID StartDepth EndDepth Strat Strand 
MD4803 0   4   CzD3 ALU 
MD4803 4   8   CzD3 SCR 
MD4803 8   12   CzD2 CIDW 
MD4803 12   14   CzD2 CIDO 
MD4803 14   18   CzD2 CIDW 
MD4803 18   22   NAM TNAM 
MD4803 22   26   NAM SNAM 
MD4803 26   30   NAM SONAM 
MD4803 30   34   NAM SNAM 
MD4803 34   38   NAM NNAM 

任何建議，將不勝感激。 謝謝。

Answer 1

使用recusive CTE，以確定A組的解決方案：

;WITH lithCTE 
AS 
(
    -- number the rows for each hole id (in case any data in the sequence is missing) 
    SELECT * , 
    ROW_NUMBER() OVER (PARTITION BY Hole_Id ORDER BY mFrom 
         ) AS rn 
    FROM #Lithology 
) 
,retCTE 
AS 
(
    --starting from the top of each hole in the dataset, identify groups 
    SELECT Hole_Id, mFrom, mTo, Strat,Strand, rn, 1 AS grp 
    FROM lithCTE 
    WHERE rn = 1 

    UNION ALL 

    SELECT l.Hole_Id, l.mFrom, l.mTo, l.Strat,l.Strand, l.rn, 
    CASE WHEN r.Hole_Id = l.Hole_id 
      AND r.strat = l.strat 
      AND r.Strand = l.Strand 
      THEN r.grp ELSE r.grp + 1 END AS grp 
    FROM retCTE AS r 
    JOIN lithCTE AS l 
    ON l.hole_id = r.hole_id AND l.rn = r.rn + 1 
) 
SELECT Hole_ID 
, MIN(mFrom) StartDepth 
, MAX(mTo) EndDepth 
, Strat, Strand 
FROM retCTE 
GROUP BY Hole_ID, Strat, Strand,grp 
ORDER BY Hole_ID,StartDepth 

有可能是一個簡單的解決方案，但在目前它躲開我。