mysql - 将 MySQL 转换为 Postgres

Question

我正在寻求帮助将我的 MySQL 查询转换为在 PostgreSQL 中工作。这是对RoR应用模型的查询。 如有任何帮助，我们将不胜感激。

SELECT * FROM( 
   SELECT @row := @row + 1 AS rownum, id, device_id, name, quarterly 
   FROM (SELECT @row :=0) r, recurrent_tests 
   WHERE device_id = "+self.id.to_s+" AND quarterly = 1
   ORDER BY name ASC
) ranked 
WHERE (rownum-1) % 4 = "+(i-1).to_s)

Answer 1

select *
from (
   select row_number() over (order by name asc) as rownum,
          id, 
          device_id, 
          name,
          quarterly
   from recurrent_tests
) t
where rownum - 1 % 4 = ...

有关窗口函数(over (...) 子句)的更多详细信息，请参阅手册:
http://www.postgresql.org/docs/current/static/tutorial-window.html