在SQL查询中一起使用union和count(*)

Question

我有一个SQL查询,看起来像这样:

select name, count (*) from Results group by name order by name

和另一个相同的,从归档结果表加载,但字段是相同的.

select name, count (*) from Archive_Results group by name order by name

如何在一个查询中将两者结合起来？(因此,群组仍将正常运作).我尝试使用union all,但是它不起作用.我错过了什么？

Answer 1

SELECT tem.name, COUNT(*) 
FROM (
  SELECT name FROM results
  UNION ALL
  SELECT name FROM archive_results
) AS tem
GROUP BY name
ORDER BY name

Answer 2

如果您有支持索引和相对较高的计数,这样的事情可能比建议的解决方案快得多:

SELECT name, MAX(Rcount) + MAX(Acount) AS TotalCount
FROM (
  SELECT name, COUNT(*) AS Rcount, 0 AS Acount
  FROM Results GROUP BY name
  UNION ALL
  SELECT name, 0, count(*)
  FROM Archive_Results
  GROUP BY name
) AS Both
GROUP BY name
ORDER BY name;

Answer 3

你的目标是......

1. 计算两个表中"Bob Jones"的所有实例(例如)
2. 要将Results一行中"Bob Jones"的所有实例和"Bob Jones"的所有实例统计 Archive_Results在一个单独的行中？

假设它是#1你想要的东西像......

SELECT name, COUNT(*) FROM
(SELECT name FROM Results UNION ALL SELECT name FROM Archive_Results)
GROUP BY name
ORDER BY name