美好的一天每個人。我一直無法提出解決方案並正在尋求任何幫助。我有,我想增加一列的表:SQL - 如何根據表中的多列添加列
ID Time_Stamp Activity_Log
1254 6/1/2013 8:00:00AM 'Ticket was opened by user A'
1254 6/2/2013 8:20:00AM 'Comment was logged by user B'
1254 6/4/2013 8:25:00AM '**Ticket was transferred to Group 1**'
1254 6/7/2013 8:50:00AM 'Comment was logged by user B'
1254 6/11/2013 10:00:00AM 'Comment was logged by user C'
1254 6/12/2013 12:00:00PM '**Ticket was transferred to Group 2**'
7589 6/3/2013 11:00:00PM 'Ticket was opened by user A'
7589 6/5/2013 1:00:00PM 'Comment was logged by user C'
7589 6/7/2013 2:00:00PM 'Resolution provided by user C'
7589 6/11/2013 5:00:00PM 'Ticket resolved by user C'
8526 6/3/2013 7:00:00PM 'Ticket opened by user D'
8526 6/4/2013 2:00:00PM '**Ticket was transferred to Group 2**'
8526 6/5/2013 1:00:00PM 'Comment was logged by user G'
8526 6/8/2013 5:00:00PM '**Ticket was resolved by user C**'
這裏就是我想新列,組,看起來像:
ID Time_Stamp Activity_Log Group
1254 6/1/2013 8:00:00AM 'Ticket was opened by user A' NULL
1254 6/2/2013 8:20:00AM 'Comment was logged by user B' NULL
1254 6/4/2013 8:25:00AM '**Ticket was transferred to Group 1**' Group 1
1254 6/7/2013 8:50:00AM 'Comment was logged by user B' Group 1
1254 6/11/2013 10:00:00AM 'Comment was logged by user C' Group 1
1254 6/12/2013 12:00:00PM '**Ticket was transferred to Group 2**' Group 2
7589 6/3/2013 11:00:00PM 'Ticket was opened by user A' NULL
7589 6/5/2013 1:00:00PM 'Comment was logged by user C' NULL
7589 6/7/2013 2:00:00PM 'Resolution provided by user C' NULL
7589 6/11/2013 5:00:00PM 'Ticket resolved by user C' NULL
8526 6/3/2013 7:00:00PM 'Ticket opened by user D' NULL
8526 6/4/2013 2:00:00PM '**Ticket was transferred to Group 2**' Group 2
8526 6/5/2013 1:00:00PM 'Comment was logged by user G' Group 2
8526 6/8/2013 5:00:00PM '**Ticket was resolved by user C**' Group 2
我想補充這如果Activity_Log是LIKE'%xx%',並且基於ID和Time_Stamp之後的每一行都包含字符串。某些ID在activity_log中將不具有該語言,並且組列對於所有行都將爲NULL。對於那些做的,我希望在activity_log開始時LIKE'%轉移到組x%',並在activity_log類似於'%轉移到組x%'或'%ticket was resolved%'時結束。我試圖用OVER(partition by)編寫一個查詢來區分ID,但我沒有成功。
謝謝
那麼......計算列?另外,哪個DBMS是這樣的? [tag:sql]有點太模棱兩可了。附:根據表的大小,您可能只需添加一個普通列,通過一次運行解析器,然後使用觸發器來保持新列同步。計算/計算的列在增加的開銷方面可能非常密集。 –
應該編寫這個「組」列是應用程序代碼而不是數據庫的責任?看起來應用程序代碼具有正確設置所需的所有信息。 –