SQL Server：比較行之間的日期

Question

我正在使用SQL Server 2016，我無法弄清楚如何構建該查詢。

比方說，我有一個表是這樣的：

ID EntryTime    ResultTime 
1 2016-05-02 13:30:00  2016-05-02 21:50:00 
2 2016-05-02 14:45:00  2016-05-02 22:00:00 
3 2016-05-02 16:30:00  2016-05-02 22:21:00 
4 2016-05-03 01:00:00  2016-05-03 03:33:00 
5 2016-05-03 10:30:00  2016-05-04 07:47:00 
6 2016-05-03 12:30:00  2016-05-03 22:45:00 
7 2016-05-04 11:30:00  2016-05-05 21:30:00 
8 2016-05-04 12:30:00  2016-05-04 22:58:00 
9 2016-05-04 13:30:00  2016-05-04 23:04:00 
10 2016-05-04 13:45:00  2016-05-04 22:59:00 
11 2016-05-04 14:00:00  2016-05-04 22:59:00 
12 2016-05-04 14:15:00  2016-05-04 23:04:00 
13 2016-05-04 17:45:00  2016-05-04 21:47:00 
14 2016-05-05 23:30:00  2016-05-06 03:25:00 
15 2016-05-05 23:45:00  2016-05-06 03:30:00 
16 2016-05-06 00:00:00  2016-05-06 03:32:00 
17 2016-05-06 00:15:00  2016-05-06 03:31:00 
18 2016-05-06 00:30:00  2016-05-06 03:25:00 
19 2016-05-06 00:45:00  2016-05-06 02:50:00 
20 2016-05-06 01:00:00  2016-05-06 03:25:00 

我想只選擇該條目日期時間是最後的選擇結果的日期時間後的行。

例如：第1行的結果時間爲「2016-05-02 21:50:00」，因此下一行將是第4行，因爲這是輸入時間在結果時間之後的第一行最後一次被選中，下一行假設是第4行的結果時間之後（在「2016-05-03 03:33:00」之後），因此下一行將是第5行。

請求的結果是：

ID EntryTime    ResultTime 
1 2016-05-02 13:30:00  2016-05-02 21:50:00 
4 2016-05-03 01:00:00  2016-05-03 03:33:00 
5 2016-05-03 10:30:00  2016-05-04 07:47:00 
7 2016-05-04 11:30:00  2016-05-05 21:30:00 
14 2016-05-05 23:30:00  2016-05-06 03:25:00 

Answer 1

您可以這樣做的一種方法是使用遞歸CTE來獲取下一行。例如，

with cte as (
    select * 
    from myTable 
    where id = 1 
    union all 
    select t.* 
    from myTable t 
    cross join cte 
    where t.id = (
     select id 
     from (
      select id, row_number() over (order by id) rn 
      from myTable 
      where entrytime > cte.resulttime) z 
     where rn = 1) 
    ) 
select * from cte; 

編輯：對於多個「符號」，這裏將工作（帶有示例數據）的方法。

DECLARE @myTable TABLE (Symbol CHAR(3), EntryTime DATETIME, ResultTime DATETIME) 
INSERT @myTable VALUES ('AAA','2016-05-02 13:30:00','2016-05-02 21:50:00') 
,('AAA','2016-05-02 14:45:00','2016-05-02 22:00:00') 
,('AAA','2016-05-02 16:30:00','2016-05-02 22:21:00') 
,('AAA','2016-05-03 01:00:00','2016-05-03 03:33:00') 
,('AAA','2016-05-03 10:30:00','2016-05-04 07:47:00') 
,('AAA','2016-05-03 12:30:00','2016-05-03 22:45:00') 
,('AAA','2016-05-04 11:30:00','2016-05-05 21:30:00') 
,('AAA','2016-05-04 12:30:00','2016-05-04 22:58:00') 
,('AAA','2016-05-04 13:30:00','2016-05-04 23:04:00') 
,('AAA','2016-05-04 13:45:00','2016-05-04 22:59:00') 
,('AAA','2016-05-04 14:00:00','2016-05-04 22:59:00') 
,('AAA','2016-05-04 14:15:00','2016-05-04 23:04:00') 
,('AAA','2016-05-04 17:45:00','2016-05-04 21:47:00') 
,('AAA','2016-05-05 23:30:00','2016-05-06 03:25:00') 
,('AAA','2016-05-05 23:45:00','2016-05-06 03:30:00') 
,('AAA','2016-05-06 00:00:00','2016-05-06 03:32:00') 
,('AAA','2016-05-06 00:15:00','2016-05-06 03:31:00') 
,('AAA','2016-05-06 00:30:00','2016-05-06 03:25:00') 
,('AAA','2016-05-06 00:45:00','2016-05-06 02:50:00') 
,('AAA','2016-05-06 01:00:00','2016-05-06 03:25:00') 
,('BBB','2016-05-02 01:00:00','2016-05-02 03:01:00') 
,('BBB','2016-05-02 02:00:00','2016-05-02 03:05:00') 
,('BBB','2016-05-02 03:00:00','2016-05-02 03:40:00') 
,('BBB','2016-05-02 04:00:00','2016-05-02 04:01:00') 
,('BBB','2016-05-02 05:00:00','2016-05-03 07:00:00') 
,('BBB','2016-05-02 06:00:00','2016-05-02 07:00:00') 
,('BBB','2016-05-03 06:00:00','2016-05-03 07:05:00') 
,('BBB','2016-05-04 06:01:00','2016-05-04 07:08:00') 
,('BBB','2016-05-04 06:07:00','2016-05-04 07:52:00') 
,('BBB','2016-05-05 06:00:00','2016-05-05 07:49:00') 
,('CCC','2016-05-05 06:00:00','2016-05-05 07:04:00') 
,('CCC','2016-05-05 06:05:00','2016-05-05 06:55:00') 
,('CCC','2016-05-05 07:00:00','2016-05-05 07:10:00') 
,('CCC','2016-05-05 07:06:00','2016-05-05 08:05:00') 
,('CCC','2016-05-05 08:00:00','2016-05-05 08:15:00') 
,('CCC','2016-05-05 08:09:00','2016-05-05 09:00:00'); 

WITH myTable AS (
    SELECT Symbol, EntryTime, ResultTime, ROW_NUMBER() OVER (PARTITION BY Symbol ORDER BY EntryTime) RN 
    FROM @myTable) 
, CTE AS (
    SELECT * 
    FROM myTable 
    WHERE RN = 1 
    UNION ALL 
    SELECT T.* 
    FROM CTE 
    CROSS APPLY (
     SELECT Symbol, EntryTime, ResultTime, RN 
     FROM (
      SELECT *, ROW_NUMBER() OVER (ORDER BY EntryTime) RN2 
      FROM myTable 
      WHERE Symbol = CTE.Symbol 
      AND EntryTime > CTE.ResultTime) Z 
     WHERE RN2 = 1) T 
    ) 
SELECT Symbol, EntryTime, ResultTime--, RN [ID?] 
FROM CTE 
ORDER BY Symbol; 

Answer 2

您可以使用此查詢：

select * 
from @t t1 
where not exists (
    select 1 
    from @t t2 
    where t2.id < t1.id and t2.resultDate > t1.entryDate 
) 

Answer 3

我有時覺得光標答案

CREATE FUNCTION getSelected 
( 
) 
RETURNS @res TABLE 
(
    id int, EntryTime DATETIME, ResultTime DATETIME 
) 
AS 
BEGIN 
    declare @idC int; 
    declare @ResultTimeC DATETIME; 
    declare @EntryTimeC DATETIME; 
    declare @lastNextDate DATETIME; 

    DECLARE Iterator CURSOR LOCAL FAST_FORWARD 
    FOR SELECT id, EntryTime, ResultTime FROM dbo.tt1 order by EntryTime, id 
    OPEN Iterator 
    WHILE 1=1 BEGIN 
     FETCH NEXT FROM Iterator INTO @idC, @EntryTimeC, @ResultTimeC 
     IF @@FETCH_STATUS < 0 BREAK 

     if(@lastNextDate is null or @lastNextDate < @EntryTimeC) begin 
      set @lastNextDate = @ResultTimeC; 
      insert into @res (id, EntryTime, ResultTime) values (@idC, @EntryTimeC, @ResultTimeC); 
     end;    
    END 
    CLOSE Iterator 
    DEALLOCATE Iterator; 

    RETURN 
END 

編輯

和多版本化符號

CREATE FUNCTION getSelected2 
( 
) 
RETURNS @res TABLE 
(
    id int, EntryTime DATETIME, ResultTime DATETIME, Symbol char(3) 
) 
AS 
BEGIN 
    declare @idC int; 
    declare @ResultTimeC DATETIME; 
    declare @EntryTimeC DATETIME; 
    declare @SymbolC char(3); 
    declare @lastNextDate DATETIME; 
    declare @lastSymbol char(3); 

    DECLARE Iterator CURSOR FAST_FORWARD 
    FOR SELECT id, EntryTime, ResultTime, Symbol FROM dbo.tt2 order by Symbol, EntryTime, id 
    OPEN Iterator 
    WHILE 1=1 BEGIN 
     FETCH NEXT FROM Iterator INTO @idC, @EntryTimeC, @ResultTimeC, @SymbolC 
     IF @@FETCH_STATUS < 0 BREAK 

     if(@lastSymbol is null or @lastSymbol <> @SymbolC) begin 
      set @lastSymbol = @SymbolC; 
      set @lastNextDate = null; 
     end; 
     if(@lastNextDate is null or @lastNextDate < @EntryTimeC) begin 
      set @lastNextDate = @ResultTimeC; 
      insert into @res (id, EntryTime, ResultTime, Symbol) values (@idC, @EntryTimeC, @ResultTimeC, @SymbolC); 
     end;    
    END 
    CLOSE Iterator 
    DEALLOCATE Iterator; 

    RETURN 
END