将两行合并为一，同时替换空值 [英] Merging two rows to one while replacing null values

问题描述

假设我有以下数据库表

Name | Nickname | ID
----------------------
Joe    Joey       14
Joe    null       14

现在，我想执行一条select语句，将这两列合并为一，同时替换空值.结果应如下所示:

Now I want to do a select statement that merges these two columns to one while replacing the null values. The result should look like this:

Joe, Joey, 14

哪个sql语句可以管理这个问题(如果可能的话)?

Which sql statement manages this (if it's even possible)?

推荐答案

最简单的解决方案:

SQL> select * from t69
  2  /

NAME       NICKNAME           ID
---------- ---------- ----------
Joe        Joey               14
Joe                           14
Michael                       15
           Mick               15
           Mickey             15

SQL> select max(name) as name
  2         , max(nickname) as nickname
  3         , id
  4  from t69
  5  group by id
  6  /

NAME       NICKNAME           ID
---------- ---------- ----------
Joe        Joey               14
Michael    Mickey             15

SQL>

如果您拥有11gR2，则可以使用新-fangled LISTAGG()函数，但否则，将上面的语句包装到SELECT中将NAME和NICKNAME列连接起来就足够简单了.

If you have 11gR2 you could use the new-fangled LISTAGG() function but otherwise it is simple enough to wrap the above statement in a SELECT which concatenates the NAME and NICKNAME columns.

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