如何在此查询中使用左联接

Question

我有以下查询

SELECT
    interview_content.title `title`,
    gallery_images.img_path img
FROM
    `interview`,
    `interview_content`,
    `gallery`,
    `gallery_images`
WHERE
    `gallery_images`.`id_parrent` = `gallery`.`id`
AND
    `gallery`.`id` =  `interview`.`gallery_id`
AND
    `gallery_images`.`default` = '1'
AND
    `interview`.`id` = `interview_content`.`id_parrent`
AND
    interview_content.id_lang = '2'
ORDER BY
    interview.date DESC

我需要在gallery、gallery_images表上使用左联接(即使没有图库或默认图像，也可以获得interview.title )。

非常感谢

更新

问题是，在第二左加入。我不能让他们正确地合作。当我尝试

SELECT
    interview_content.title `title`,
    gi.img_path img
FROM
    `interview`,
    `interview_content`
LEFT JOIN `gallery` as g ON g.`id` = `interview`.`gallery_id` 
LEFT JOIN `gallery_images` as gi ON gi.id_parrent = g.`id`
WHERE
    `interview`.`id` = `interview_content`.`id_parrent`
AND
    interview_content.id_lang = '2'
ORDER BY
    interview.date DESC

it returns //Unknown column 'interview.gallery_id' in 'on clause'

Answer 1

不要混合ANSI-89和ANSI-92样式的联接.

我发现了同样的问题，here。

所以我的查询必须如下所示

SELECT
    ic.title `title`,
    gi.img_path img
FROM
    `interview` i
JOIN interview_content ic  on ic.id_parrent =  i.id AND ic.id_lang = '2'
LEFT JOIN `gallery` as g ON g.`id` = i.`gallery_id` 
LEFT JOIN `gallery_images` as gi ON gi.id_parrent = g.`id`
AND gi.`default` = '1'
WHERE
    i.`id` = ic.`id_parrent`
OPRDER BY
    `i`.`date` DESC

Answer 2

你知道你需要做什么。谷歌是你的朋友吗？

http://en.wikipedia.org/wiki/Join_%28SQL%29#Left_outer_join

Answer 3

试试那个：

SELECT
    interview_content.title `title`,
    gallery_images.img_path img
FROM
    `interview`,
    `interview_content`,
LEFT JOIN `gallery` ON (`interview`.`gallery_id` = `gallery`.`id` AND `gallery_images`.`default` = '1'), 
LEFT JOIN `gallery_images` ON `gallery`.`id` = `gallery_images`.`id_parrent`
WHERE
    `interview`.`id` = `interview_content`.`id_parrent`
AND
    interview_content.id_lang = '2'
ORDER BY
    interview.date DESC;