什麼是火鳥的MySQL中FIRST和LAST的等價函數

有誰知道MySQL和Firebird的集合函數FIRST和LAST的等價性。我有這樣的庫存主表看起來像這樣：什麼是火鳥的MySQL中FIRST和LAST的等價函數

DATE  |ITEM_CODE  | BEG | + | - | - | - | + | + | + | + | - | - | END 
2015-10-27 | 000000000MS016 |12.5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 12.5 
2015-10-27 | 000000000PN044 | 0 |10 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 10 
2015-10-27 | 000000000VI064 | 440 | 5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 445 
2015-10-27 | 000000000VI029 | 274 | 0 | 5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 269 

2015-10-28 | 000000000MS016 |12.5 |20 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 32.5 
2015-10-28 | 000000000PN044 | 10 |50 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 60 
2015-10-28 | 000000000VI064 | 445 | 0 | 0 |10 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 435 
2015-10-28 | 000000000VI029 | 269 | 0 | 0 | 0 |20 | 0 | 0 | 0 | 0 | 0 | 0 | 249 

2015-10-29 | 000000000MS016 |32.5 | 0 |10 | 0 | 0 | 0 | 0 | 0 |30 | 0 | 5 | 47.5 
2015-10-29 | 000000000PN044 | 60 | 5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 65 
2015-10-29 | 000000000VI064 | 435 | 0 | 0 | 0 | 0 |10 | 0 | 0 | 0 | 8 | 0 | 437 
2015-10-29 | 000000000VI029 | 249 |35 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 4 | 280 

2015-10-30 | 000000000MS016 |47.5 | 0 |15 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 32.5 
2015-10-30 | 000000000PN044 | 65 | 5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 5 | 0 | 65 
2015-10-30 | 000000000VI064 | 437 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 437 
2015-10-30 | 000000000VI029 | 280 | 0 | 5 | 0 | 5 | 0 | 0 | 6 | 0 | 3 | 0 | 273

，我有這個SELECT條款：

SELECT 
    INV.ITEM_CODE, 
    FIRST(INV.BEG_QTY) AS BEG_QTY, 
    SUM(INV.REC_QTY) AS REC_QTY, 
    SUM(INV.RET_QTY) AS RET_QTY, 
    SUM(INV.SOLD_QTY) AS SOLD_QTY, 
    SUM(INV.BO_QTY) AS BO_QTY, 
    SUM(INV.ADJ_QTY) AS ADJ_QTY, 
    SUM(INV.COUNT_P) AS COUNT_P, 
    SUM(INV.COUNT_C) AS COUNT_C, 
    SUM(INV.TRANS_IN) AS TRANS_IN, 
    SUM(INV.TRANS_OUT) AS TRANS_OUT, 
    SUM(INV.DELIVERY) AS DELIVERY, 
    LAST(INV.END_QTY) AS END_QTY 
FROM INV_MASTER INV 
WHERE (INV.INV_DATE BETWEEN '2015-10-27' AND '2015-10-31') 
GROUP BY INV.ITEM_CODE 
ORDER BY INV.ITEM_CODE

，結果應該是這樣的：

ITEM_CODE  | BEG | + | - | - | - | + | + | + | + | - | - | END  
000000000MS016 |12.5 |20 |25 | 0 | 0 | 0 | 0 | 0 |30 | 0 | 5 | 32.5 
000000000PN044 | 0 |70 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 5 | 0 | 65 
000000000VI064 | 440 | 5 | 0 |10 | 0 |10 | 0 | 0 | 0 | 8 | 0 | 437 
000000000VI029 | 274 |35 |10 | 0 |25 | 0 | 0 | 6 | 0 | 3 | 4 | 273

但我m有FIRST和LAST聚合函數的問題，我使用的是firebird v2.5。我怎樣才能做到這一點？

來源

2016-02-03 Karen D

FIRST＆LAST不是標準的，因爲表中沒有順序，只有在一個外部ORDER BY之後的最終結果。你知道他們從哪個版本的SQL？你期望他們做什麼？爲什麼不使用DATE的MIN＆MAX？ – philipxy

@philipxy我只是在某處讀過它，FIRST應該得到它從結果中得到的第一個值（在我的案例中是來自INV_DATE 2015-10-27的值），最後應該得到最後一個值（ 'INV_DATE 2015-10-30'）。所以你認爲應該是我的問題？ –

你還沒有清楚說明「第一」和「最後」是什麼意思。當表格無序時，什麼是「第一價值」？也許涉及到日期？您的輸入是否以某種方式排列，並且您正在呼籲該訂單？我仍然無法看到你的輸出是輸入的函數。請結束以下語句：當...＆同時輸入時，行屬於所需的輸出。 – philipxy

你應該能夠

(SELECT END_QTY FROM INV_MASTER 
    WHERE ITEM_CODE = INV.ITEM_CODE 
    AND INV_DATE = MAX(INV.INV_DATE)) AS END_QTY

更換使用LAST這將選擇當前項目的END_QTY，與該項目的最高日期。

來源

2016-02-03 09:14:02

耶！有效！非常感謝，@MarkRotteveel：3 –

什麼是火鳥的MySQL中FIRST和LAST的等價函數

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