我想做一个嵌套的选择,但不同的表。这里是我的查询:从不同的表嵌套选择
SELECT contact_profile.name, main_app.fk_lkp_app, main_app.id as main_id,
(
-- if the main_app.fk_lkp_app value is 1 then do this
SELECT SUM(translation_app.amount)
FROM translation_app
WHERE translation_app.fk_main_app = main_app.id
AND translation_app.status = 2
AND main_app.srf_number is not null
AND main_app.fk_invoice is not null
-- if the main_app.fk_lkp_app value is 2 then do this
SELECT SUM(interpretation_app.amount)
FROM interpretation_app
WHERE interpretation_app.fk_main_app = main_app.id
AND interpretation_app.status =2
AND main_app.srf_number is not null
AND main_app.fk_invoice is not null
-- if the main_app.fk_lkp_app value is 3 then do this
SELECT SUM(course_app.amount)
FROM course_app
WHERE course_app.fk_main_app = main_app.id
AND course_app.status =2
AND main_app.srf_number is not null
AND main_app.fk_invoice is not null
) as amount
FROM contact_profile
LEFT JOIN main_app ON main_app.fk_contact_profile = contact_profile.id
WHERE main_app.fk_lkp_app in (1,2,3)
AND main_app.srf_number is not null
AND main_app.fk_invoice is not null
GROUP BY contact_profile.name
ORDER BY amount DESC
正如你所看到的,“量”字段基于main_app.fk_lkp_app值不同的表中选择。问题是如何做这个查询的最佳方法?我坚持使用“main_app.fk_lkp_app”值参数部分。
我甚至使用CASE尝试作为建议,但它不断给我的错误代码#1064
SELECT contact_profile.name, main_app.fk_lkp_app, main_app.id as main_id,
(
CASE
WHEN main_app.fk_lkp_app = '1'
THEN (
SELECT SUM(translation_app.amount)
FROM translation_app
WHERE translation_app.fk_main_app = main_app.id
)
WHEN main_app.fk_lkp_app = '2'
THEN (
SELECT SUM(interpretation_app.amount)
FROM interpretation_app
WHERE interpretation_app.fk_main_app = main_app.id
)
WHEN main_app.fk_lkp_app = '3'
THEN (
SELECT SUM(course_app.amount)
FROM course_app
WHERE course_app.fk_main_app = main_app.id
)
ELSE 0
END CASE
) as amount
FROM contact_profile
LEFT JOIN main_app ON main_app.fk_contact_profile = contact_profile.id
WHERE main_app.fk_lkp_app in (1,2,3)
AND main_app.srf_number is not null
AND main_app.fk_invoice is not null
GROUP BY contact_profile.name
ORDER BY amount DESC
奇怪的是,如果我不使用的情况下,仅使用1从3变体中(例如:我只从translation_app表中选择)查询正在工作。
根据您的查询,嵌套的选择结果对于主要查询的输入而言不是必需的,因此您需要将这些嵌套的查询转换为加入。 –
你可以使用'CASE'吗? –
我该如何做到这一点?我可以加入,但不同的main_app.fk_lkp_app价值要求困扰着我。 – IkouKuhn