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如何在MS-Access中選擇具有相同非唯一ID的兩個多行的第一個數據集?MS-Access選擇非唯一ID的第一行
我沒有用非唯一ID來設計這個混亂,並且除ID以外的其他字段都是隨機字符串值,因此可能是唯一的或重複的。
說我有輸入表
Tab_INPUT
--------------------------
| ID | VAL1 | VAL2 | ... |
- - - - - - - - - - - - -
| 1 | "A" | "1a" | ... |
| 2 | "B" | "2b" | ... |
| 2 | "C" | "2a" | ... |
| 3 | "D" | "3c" | ... |
| 3 | "E" | "3b" | ... |
| 3 | "F" | "3a" | ... |
| 4 | "G" | "4a" | ... |
--------------------------
我現在要選擇爲每個不同的ID的第一行,這樣即
Tab_OUTPUT (DESIRED)
--------------------------
| ID | VAL1 | VAL2 | ... |
- - - - - - - - - - - - -
| 1 | "A" | "1a" | ... |
| 2 | "B" | "2b" | ... |
| 3 | "D" | "3c" | ... |
| 4 | "G" | "4a" | ... |
--------------------------
我不能使用類似
SELECT ID, Min(VAL1), Min(Val2) FROM Tab_INPUT GROUP BY ID
因爲這會弄亂行本身
Tab_OUTPUT (WRONG)
--------------------------
| ID | VAL1 | VAL2 | ... |
- - - - - - - - - - - - -
| 1 | "A" | "1a" | ... |
| 2 | "B" | "2a" | ... |
| 3 | "D" | "3a" | ... |
| 4 | "G" | "4a" | ... |
--------------------------
我需要的行itsself保持完好,只是選擇先用一個唯一的ID
易是真實的...工程就像一個魅力,謝謝! – HeXor