我想从wordpress DB中进行选择

Question

db的结构如下：

id | meta-key | meta-value

1  | client   | John

1  | bday     | today

我想让它成为

id | client | bday

1  | John   | today

有许多行，比如client和bday，我想在显示或插入到另一个表时将它们中的一些转换为列

我尝试了这样的东西：

SELECT p1.meta_value, wph0_posts.post_title, p2.meta_value as client, p3.meta_value as end_date, p4.meta_value as description
FROM wph0_postmeta p1
INNER JOIN wph0_posts ON p1.post_id = wph0_posts.ID
INNER JOIN wph0_postmeta p2 ON
p1.post_id = p2.post_id AND
p2.meta_key = 'client'
INNER JOIN wph0_postmeta p3 ON
p1.post_id = p3.post_id AND
p3.meta_key = 'end_date'
INNER JOIN wph0_postmeta p4 ON
p1.post_id = p4.post_id AND
p4.meta_key = 'description';

能给我点建议吗？对db‘’es非常陌生

Answer 1

Thx要获得帮助，请执行以下操作：

SELECT wph0_postmeta.post_id, 
GROUP_CONCAT( if(wph0_postmeta.meta_key='client',wph0_postmeta.meta_value,NULL) ) AS Nume, 
GROUP_CONCAT( if(wph0_postmeta.meta_key='end_date',wph0_postmeta.meta_value,NULL) ) AS Descriere 
FROM wph0_postmeta GROUP BY wph0_postmeta.post_id

我只从wph0_postmeta中提取了名称和一些东西，并使用了if语句。我现在可以添加另一个group_concat，并从一个meta_key添加另一个列，我在这里获得了pivots的链接：

Need Table Values as Column Titles