mysql - 合并结果并用逗号分隔

Question

我有这个查询:

SELECT
  tud.detail_company_name AS company_name,
  tud.detail_country AS company_country,
  trv.review_title AS review_title
FROM users_detail tud
INNER JOIN users_auth tua
  ON tud.user_id = tua.user_id
LEFT JOIN reviews trv
  ON tud.user_id = trv.review_company_id
WHERE
  tua.auth_user_type = "company" OR tua.auth_user_type = "guestcompany"

查询工作正常，它返回如下结果:

Array
(
    [0] => Array
        (
            [company_name] => The Coffee Brewery
            [company_country] => US
            [review_title] => 
        )
    [1] => Array
        (
            [company_name] => Crea Nail Art Studio
            [company_country] => SG
            [review_title] => 
        )
    [2] => Array
        (
            [company_name] => Hello Mall
            [company_country] => JP
            [review_title] => Fake goods!
        )
    [3] => Array
        (
            [company_name] => Hello Mall
            [company_country] => JP
            [review_title] => Never buy in there!
        )
)

正如您所注意到的，数组键 2 和 3 具有相同的 company_name，但 review_title 不同。是否有可能必须将其连接到一个结果中并用逗号分隔？举例来说这个结果:

Array
(
    [0] => Array
        (
            [company_name] => The Coffee Brewery
            [company_country] => US
            [review_title] => 
        )
    [1] => Array
        (
            [company_name] => Crea Nail Art Studio
            [company_country] => SG
            [review_title] => 
        )
    [2] => Array
        (
            [company_name] => Hello Mall
            [company_country] => JP
            [review_title] => Fake goods!, Never buy in there!
        )
)

编辑

如果响应是这样怎么办:

Array
(
    [0] => Array
        (
            [company_name] => The Coffee Brewery
            [company_country] => US
            [review_title] => 
            [review_approved] =>
        )
    [1] => Array
        (
            [company_name] => Crea Nail Art Studio
            [company_country] => SG
            [review_title] => 
            [review_approved] =>
        )
    [2] => Array
        (
            [company_name] => Hello Mall
            [company_country] => JP
            [review_title] => Fake goods!
            [review_approved] => 1
        )
    [3] => Array
        (
            [company_name] => Hello Mall
            [company_country] => JP
            [review_title] => Never buy in there!
            [review_approved] => 0
        )
)

如何才能不在 review_title GROUP_CONCAT 中包含 0 review_approved？那么它会输出这样的吗？

Array
(
    [0] => Array
        (
            [company_name] => The Coffee Brewery
            [company_country] => US
            [review_title] => 
        )
    [1] => Array
        (
            [company_name] => Crea Nail Art Studio
            [company_country] => SG
            [review_title] => 
        )
    [2] => Array
        (
            [company_name] => Hello Mall
            [company_country] => JP
            [review_title] => Fake goods!
        )
)

Answer 1

是的。使用GROUP_CONCAT():

SELECT
  tud.detail_company_name AS company_name,
  tud.detail_country AS company_country,
  GROUP_CONCAT(trv.review_title SEPARATOR ',') AS review_titles
FROM users_detail tud
INNER JOIN users_auth tua
  ON tud.user_id = tua.user_id
LEFT JOIN reviews trv
  ON tud.user_id = trv.review_company_id
WHERE
  tua.auth_user_type = :company OR tua.auth_user_type = :guestcompany
GROUP BY 
    tud.detail_company_name,
    tud.detail_country;