MySQL从单独的表中获取count（）

Question

我试图通过一个查询在三个不同的MySQL表中获得简单的行数。这就是我所拥有的：

SELECT count(s.`id`) AS c1,
       count(g.`id`) AS c2,
       count(r.`id`) AS c3
  FROM table1 s,
       table2 g,
       table3 r

虽然这不起作用，但我认为它会增加所有三个总数。谢谢你的帮助。

Answer 1

如果表没有关系，则无法加入，请尝试：

SELECT
  (select count(id) from table1) as c1,
  (select count(id) from table2) as c2,
  (select count(id) from table3) as c3