Question

我有两个表，用户和hra。用户在用户表中只能有一条记录，但他可以有多个hras。我想要做的只是每个用户检索一个hra。我有以下查询。任何人都可以帮忙做到这一点？

$query = "SELECT u.id AS user_id, h.id AS hra_id FROM users u
          INNER JOIN hra h ON u.id = h.user_id
          WHERE h.date BETWEEN ? AND ?
          AND h.done = 1

Answer 1

假设你想要MAX（h.id），这应该有效：

SELECT u.id AS user_id, MAX(h.id) AS hra_id FROM users u
      INNER JOIN hra h ON u.id = h.user_id
      WHERE h.date BETWEEN ? AND ?
      AND h.done = 1
 GROUP BY u.id

如何为每个用户选择一条记录？

1 个答案: