sql - 将 Postgres 查询结果合并到一个表中

Question

我有两个有效的 Postgres 查询。

SELECT date_trunc('hour', time) t, COUNT(*) AS "SC15" FROM logfile
      WHERE source = 'SC15' AND type = 'Sort'
      GROUP BY t ORDER BY t;

SELECT date_trunc('hour', time) t, COUNT(*) AS "SC71" FROM logfile
      WHERE source = 'SC71' AND type = 'Sort'
      GROUP BY t ORDER BY t;

如何让结果在单独的列中并排显示？按小时分组的 t(间隔)列、SC15 列和 SC17 列。我试过 UNION 和 INTERSECT。我想我需要做一个临时表？不确定如何。谢谢!

Answer 1

没有必要在两个查询中这样做

SELECT 
    date_trunc('hour', time) t,
    COUNT(*) FILTER (WHERE source = 'SC15') AS "SC15", 
    COUNT(*) FILTER (WHERE source = 'SC71') AS "SC71" 
FROM logfile
WHERE source IN ('SC15', 'SC71') AND type = 'Sort'
GROUP BY t
ORDER BY t

IN 运算符允许您过滤多个值。 FILTER 子句在计数之前过滤掉一些行。