mysql - 应返回多个的单个数组

Question

phpmyadmin 中的以下查询根据我的需要返回具有三个不同条目 ID 的三列 (entry_id)。

SELECT sub_1.entry_id, sub_2.entry_id, sub_3.entry_id
FROM exp_judging_portfolios AS jud
LEFT JOIN exp_submissions AS sub_1 ON sub_1.id = jud.rel_id_1
LEFT JOIN exp_submissions AS sub_2 ON sub_2.id = jud.rel_id_2
LEFT JOIN exp_submissions AS sub_3 ON sub_3.id = jud.rel_id_3
WHERE sub_1.member_group = $member_group
AND jud.pre = 1
GROUP BY jud.rel_id_1

但是，当我在页面中返回结果时，我得到一个仅包含一个条目 id 的数组。

这是我用来生成结果的代码

$sql = "
    SELECT sub_1.entry_id, sub_2.entry_id, sub_3.entry_id
    FROM exp_judging_portfolios AS jud
    LEFT JOIN exp_submissions AS sub_1 ON sub_1.id = jud.rel_id_1
    LEFT JOIN exp_submissions AS sub_2 ON sub_2.id = jud.rel_id_2
    LEFT JOIN exp_submissions AS sub_3 ON sub_3.id = jud.rel_id_3
    WHERE sub_1.member_group = $member_group
    AND jud.pre = 1
    GROUP BY jud.rel_id_1
";
    $query = $this->EE->db->query($sql);
    $submissions_portfolio = $query->result_array();    

print_r($submissions_portfolio);   

这是返回的内容:

Array ( [0] => 354 ) 

有人知道为什么吗？如果是这样，如何返回所有 3 个条目 id？

Answer 1

这次您只得到一个结果的原因是，所有 3 个选定的 id 都具有相同的别名 entry_id。它们最终会互相覆盖。

您应该尝试以不同的方式命名它们:

选择 sub_1.entry_id AS id_1、sub_2.entry_id AS id_2、sub_3.entry_id AS id_3