将两行合并为一行，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

现在我想做一个选择语句，将这两列合并为一，同时替换空值.结果应该是这样的:

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 语句管理这个(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>

如果您有 11gR2，您可以使用 新的-奇怪的 LISTAGG() 函数 但除此之外，将上述语句包装在连接 NAME 和 NICKNAME 列的 SELECT 中很简单.

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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