如何将列数据转换为php mysql中的行

Question

这基本上是为了测试地址簿php应用程序。这是我从SQL查询中得到的输出。我想把这个结果转换成一行。

MySQL查询输出

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输出寻找

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Answer 1

查询

SELECT contact_id,
MAX(First_name) AS First_name,
MAX(Last_Name) AS Last_Name,
MAX(Primary_Email) AS Primary_Email,
MAX(Primary_phone) AS Primary_phone
FROM (
SELECT MIN(contact_id) as contact_id,
CASE WHEN meta_data='First_Name' THEN meta_value END AS First_Name,
CASE WHEN meta_data='Last_Name' THEN meta_value END AS Last_Name,
CASE WHEN meta_data='Primary_Email' THEN meta_value END AS Primary_Email,
CASE WHEN meta_data='Primary_phone' THEN meta_value END AS Primary_phone
FROM tbl
GROUP BY contact_id,meta_data,meta_value
) t
GROUP BY contact_id

小提琴演示

Answer 2

请尝试执行以下查询。假设postmeta是表名

select a.contact_id,b.meta_value,c.meta_value,d.meta_value,e.meta_value
from postmeta a 
join postmeta b on (a.contact_id=b.contact_id and b.meta_date='First_Name')
join postmeta c on (a.contact_id=c.contact_id and c.meta_date='Last_Name')
join postmeta d on (a.contact_id=d.contact_id and d.meta_date='Primary_Email')
join postmeta e on (a.contact_id=e.contact_id and d.meta_date='Primary_Phone')