MySQL 从单独的表中获取 count()

Question

我试图通过单个查询获取三个不同 MySQL 表中的简单行数。这是我所拥有的:

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，但我认为它是将所有三个总数相乘。感谢您的帮助。

Answer 1

如果表没有关系且无法连接，试试这个:

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