嗨,我有兩個表代理,技能和目標查詢,如下SQL和列名替換單元格的值,避免空值
代理
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PF |Name |HireDate |
---------|-----------|---------------|
54 |Jack |01-Jan-2012 |
55 |Aline |01-Jan-2012 |
-------------------------------------
技能
-------------------------------------------------------------
PF |Writing |Swimming |KickOff |Shopping |
---------|-----------|---------------|-----------------------
54 |Null |01-Dec-2012 |Null |Null |
55 |01-Mar-2012|01-FeB-2012 |Null |15-Nov-2012|
-------------------------------------------------------------
我想查詢從代理商表中選擇PF,從技能表中選擇可用技能。技能表上的日期意味着代理商在這些數據上學到了這項技能,但是如果有空值,這意味着代理商沒有身手,但我想更換日期列名如下表explane什麼是我的查詢
更改爲MyQuery
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PF |HireDate |Avalivble skills |
---------|---------------|----------------------------|
54 |01-Jan-2012 |Swimming |
55 |01-Jan-2012 |Writing, Swimming, Shopping |
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什麼[RDBMS](http://en.wikipedia.org/wiki/Relational_database_management_system)您正在使用? 'SQL Server'? 'MySQL'? 'Oracle'? 'DB2'?等等...... –
M.S.訪問2010 – KaZzA