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这是我的查询..

SELECT tcs.tutor_id AS tid, tcs.category_id AS cid, tcs.subject_id AS sid, GROUP_CONCAT( DISTINCT s.subjects SEPARATOR ', ') AS subjects,
t.tutor_name, t.tutor_code AS tcode, DATE_FORMAT(t.registration_date, '%b %D, %Y') AS date, t.qualification,
GROUP_CONCAT( DISTINCT o.option_name SEPARATOR ', ') AS tutor_option, timg.image_name AS img
FROM tutor_category_subject as tcs
INNER JOIN subject AS s ON tcs.subject_id = s.subject_id
INNER JOIN tutor_option AS toption ON toption.tutor_id = tcs.tutor_id
INNER JOIN options AS o ON toption.option_id = o.option_id
INNER JOIN tutors AS t ON tcs.tutor_id = t.tutor_id
LEFT JOIN tutor_images AS timg ON timg.tutor_id = tcs.tutor_id
WHERE s.subjects LIKE '%business%' AND timg.image_type = 'profile'
GROUP BY tcs.tutor_id;

此查询正常工作.. 但是 timg 的 image_type coloum 存在问题。这是导师可能有他们的个人资料图片，有些导师没有个人资料图片。但是我需要选择所有具有这种条件的导师，即使不是他们的个人资料图片。在这个查询中，如果没有导师没有选择的导师的个人资料图片......那么我该怎么做......？

非常感谢任何评论。谢谢

4

2 回答 2

3

您只需将子句中的过滤器移动WHERE到JOIN子句 for tutor_images：

SELECT tcs.tutor_id AS tid, tcs.category_id AS cid, tcs.subject_id AS sid, GROUP_CONCAT( DISTINCT s.subjects SEPARATOR ', ') AS subjects,
t.tutor_name, t.tutor_code AS tcode, DATE_FORMAT(t.registration_date, '%b %D, %Y') AS date, t.qualification,
GROUP_CONCAT( DISTINCT o.option_name SEPARATOR ', ') AS tutor_option, timg.image_name AS img
FROM tutor_category_subject as tcs
INNER JOIN subject AS s ON tcs.subject_id = s.subject_id
INNER JOIN tutor_option AS toption ON toption.tutor_id = tcs.tutor_id
INNER JOIN options AS o ON toption.option_id = o.option_id
INNER JOIN tutors AS t ON tcs.tutor_id = t.tutor_id
LEFT JOIN tutor_images AS timg ON timg.tutor_id = tcs.tutor_id AND timg.image_type = 'profile'
WHERE s.subjects LIKE '%business%' 
GROUP BY tcs.tutor_id;
于 2012-10-31T13:39:34.547 回答
1

您也可以在以下WHERE部分执行此操作：

WHERE s.subjects LIKE '%business%' AND (timg.image_type = 'profile' OR timg.image_type is NULL)
于 2012-10-31T13:43:26.080 回答