MySQL-将具有特定字符串的行放入列中
我想得到4个结果,通常在4行中返回,而在2行中返回 我有一个疑问:MySQL-将具有特定字符串的行放入列中,mysql,sql,Mysql,Sql,我想得到4个结果,通常在4行中返回,而在2行中返回 我有一个疑问: SELECT meta_key, meta_value, t.post_date_gmt FROM (SELECT * FROM dr_posts JOIN dr_postmeta ON post_id = ID WHERE post_author = 2 AND post_type ='donation') AS t WHERE meta_key = '_donation_amount' OR meta_key= '_ano
SELECT meta_key, meta_value, t.post_date_gmt FROM (SELECT *
FROM dr_posts
JOIN dr_postmeta ON post_id = ID
WHERE post_author = 2
AND post_type ='donation') AS t WHERE meta_key = '_donation_amount' OR meta_key= '_anonymous_donation'
返回:
=======================================================
| meta-key | meta-value | post_date_gmt |
=======================================================
| _anonymous_donation | 0 | 2015-03-01 |
| _donation_amount | 10 | 2015-03-01 |
| _anonymous_donation | 0 | 2015-03-02 |
| _donation_amount | 15 | 2015-03-02 |
_______________________________________________________
我真正想要的(列名并不重要,只是结果):
如何做到这一点?我读到我需要使用PIVOT,但我不确定这是否是我真正需要的。我认为这可能会有所帮助
select min(meta-value) as _anonymous_donation,
max(meta-value) as _donation_amount,
post_date_gmt
from table
group by post_date_gmt
我认为这个查询应该满足您的要求:
select
max(case when meta_key = '_anonymous_donation' then meta_value end) as '_anonymous_donation',
max(case when meta_key = '_donation_amount' then meta_value end) as '_donation_amount',
post_date_gmt
from (SELECT *
FROM dr_posts
JOIN dr_postmeta ON post_id = ID
WHERE post_author = 2
AND post_type ='donation'
) AS t
WHERE meta_key = '_donation_amount' OR meta_key= '_anonymous_donation'
group by post_date_gmt
“示例表数据会让一切变得更清晰。@jarlh,您想要什么样的示例数据?请尝试提供一些示例数据,例如在运行查询时所拥有的数据中。
select
max(case when meta_key = '_anonymous_donation' then meta_value end) as '_anonymous_donation',
max(case when meta_key = '_donation_amount' then meta_value end) as '_donation_amount',
post_date_gmt
from (SELECT *
FROM dr_posts
JOIN dr_postmeta ON post_id = ID
WHERE post_author = 2
AND post_type ='donation'
) AS t
WHERE meta_key = '_donation_amount' OR meta_key= '_anonymous_donation'
group by post_date_gmt