id lat long speed date address
1 22.92138131 72.44103313 3.96 km/h 2011-09-26 National, Gujarat, India
2 22.92138145 72.44103413 13.96 km/h 2011-09-26 National, Gujarat, India
3 22.92138134 72.44103423 15.96 km/h 2011-09-26 National, Gujarat, India
4 22.92138454 72.44103233 13.96 km/h 2011-09-26 10t ring Rd, Nehru Nagar
5 22.92138354 72.44102533 13.96 km/h 2011-09-26 Anandnagar Rd, Ahmedabad
6 22.92138484 72.44103293 19.96 km/h 2011-09-26 Anandnagar Rd, Ahmedabad
重複行我想編寫一個查詢,使得我的結果是這樣的:刪除從表
id lat long speed date address
1 22.92138131 72.44103313 3.96 km/h 2011-09-26 National, Gujarat, India
4 22.92138454 72.44103233 13.96 km/h 2011-09-26 10t ring Rd, Nehru Nagar
5 22.92138354 72.44102533 13.96 km/h 2011-09-26 Anandnagar Rd, Ahmedabad
我想根據地址刪除重複的行。
請仔細閱讀http://en.wikipedia.org/wiki/Database_normalization – YXD
如果地址重複,您希望返回結果集中的哪一行?首先通過ID? –
身份證2在不重複任何其他行..你爲什麼要刪除這也.. –