加入派生表與自身

我有事件表： [TBL]

time | newState 
1200 | 1 
1300 | 2 
1400 | 5

我需要把這個表格轉換爲間隔表[間隔]：

t0 | t1 | state 
1200 | 1300 | 1 
1300 | 1400 | 2

限制：SQL COMPACT EDITION

查詢：

SELECT leftPart.time AS t0, min(rightPart.time) AS t1, leftPart.newState 
FROM tbl AS leftPart 
LEFT OUTER JOIN tbl As rightPart 
ON leftPart.time<rightPart.time 
GROUP BY leftPart.Time,leftPart.newState

當[tbl]是數據庫中的永久表時它工作的很好，但在我的情況下[tbl]是從另一個select子查詢派生的！像這樣：

(SELECT time,newState 
from ...) AS derivedTb

所以，當我嘗試這樣：

SELECT derivedTbl.time As t0,derivedTbl.state,min(rigthTblPart.time) FROM 
(SELECT time,newState 
from ...) AS derivedTbl 
LEFT OUTER JOIN with derivedTbl AS rigthTblPart 
ON derivedTbl.Time<rightTblPart.Time ...

它拋出錯誤：「derivedTbl不存在」 ...

看來，派生表下它的別名是不可見的更高級別的查詢（謝謝谷歌翻譯！））...

有什麼辦法來存儲派生的表在查詢中，並在查詢的不同部分使用它們？ SQL CE不支持臨時表，視圖和公共表表達式...

任務的詳細信息（如果有趣）： 我有2個表事件：

[states1] 
time | state1 
1200 | 1 
1300 | 2 
1400 | 3 

[states2] 
time | state2 
1200 | 0 
1230 | 10 
1330 | 20 
1430 | 30

我需要轉換他們間隔表：皈依的

[intervals] 
t0  t1  state1 state2 
1200 1230 1 0 
1230 1300 1 10 
1300 1330 2 10 
1330 1400 2 20 
1400 1430 3 20 
1430 NULL 3 30

階段： 1.整體的時間表

(SELECT Time FROM States1 
UNION 
SELECT Time FROM States2) AS timetbl

加入States1表
加入國家2臺

這一刻一切順利：

SELECT  states12tbl.time, states12tbl.state1, states2tbl.State AS state2 
    FROM   (SELECT  states12tbl_1.time, states12tbl_1.state1, MAX(states2tbl.Time) AS states2time 
     FROM   (SELECT  timetbl.time, states1tbl.State AS state1 
      FROM   (SELECT  timetbl_1.Time AS time, MAX(States1tbl.Time) AS state1time 
       FROM   (SELECT  Time 
        FROM   States1 
        UNION 
        SELECT  Time 
        FROM   States2) AS timetbl_1 LEFT OUTER JOIN 
        States1 AS States1tbl ON States1tbl.Time <= timetbl_1.Time 
       GROUP BY timetbl_1.Time) AS timetbl INNER JOIN 
       States1 AS states1tbl ON timetbl.state1time = states1tbl.Time

加入表本身...這是問題，我需要自己加入代碼（3），因爲sql ce不能記住臨時表......如果你有更好的主意，請分享:)

來源

2011-07-04 Artyom Chernetsov

SQL CE版本3。5 –

由於SQL CE的限制，您必須發佈完整的子查詢，我們會看看我們是否可以做些什麼。否則，你必須寫子查詢兩次.. –

似乎唯一的選擇是編寫子查詢兩次，因爲沒有辦法在sql ce中存儲臨時表......子查詢真的很難:) ... –

根據您的第一個SELECT創建視圖。

來源

2011-07-04 08:22:01 Gedrox

sql ce不支持視圖...或不？ :) ... –

最初沒有指定引擎。 – Gedrox

-1

Onotole，我認爲這是一個麻煩。

重寫此查詢像

SELECT 
    derivedTbl.time As t0, 
    derivedTbl.state, 
    min(rigthTblPart.time) 
FROM 
    (SELECT time,newState from ...) AS derivedTbl 
    LEFT OUTER JOIN derivedTbl AS rigthTblPart 
     ON derivedTbl.Time<rightTblPart.Time 
....

來源

2011-07-04 08:32:48

它會顯示一個錯誤：「derivedTbl does not exist」...它不記得像臨時表的子查詢 –

加入派生表與自身

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