PostgreSQL:枚举SQL查询结果

Question

请考虑以下SQL查询和响应:

CREATE TEMPORARY TABLE dreams (name text, type text);
INSERT INTO dreams VALUES ('Monkey', 'nice');
INSERT INTO dreams VALUES ('Snake', 'Not nice');
INSERT INTO dreams VALUES ('Donkey', 'nice');
INSERT INTO dreams VALUES ('Bird', 'nice');

SELECT name from dreams WHERE type='nice' ORDER BY name;
  name
--------
 Bird
 Donkey
 Monkey
(3 rows)

为方便起见,我想按照外观的顺序列举结果,而不管任何现有的ID.预期的结果应该是a-la:

SELECT <magic_enumeration>, name from dreams WHERE type='nice' ORDER BY name;

 magic_enumeration |  name
-------------------+--------
 1                 | Bird
 2                 | Donkey
 3                 | Monkey
(3 rows)    

有关如何按外观顺序枚举查询结果的任何想法？

Answer 1

尝试使用row_number,这是一个窗口函数

SELECT row_number() OVER (ORDER BY name) sid, <-- magic enumeration!
       name 
  FROM dreams 
  WHERE type='nice' 
  ORDER BY name;