如何从 wordpress 表中获取 SQL 查询

Question

我有一个 sql 查询，但没有找到正确的解决方案。

查询有效，但它没有显示wp_usermeta表的列，只显示wp_users的列。

如果我删除where子句，将显示所有列的所有值的行，但我只需要取决于meta_value = "Prod"列中的 meta.key = 'kennung_produzent' 的行

SELECT p.ID,
       p.user_login,
       p.user_registered,
       p.display_name,
        max( CASE WHEN pm.meta_key = 'nickname' and p.ID = pm.user_id THEN pm.meta_value END ) as Nickname,
        max( CASE WHEN pm.meta_key = 'billing_email' and p.ID = pm.user_id THEN pm.meta_value END ) as email,
        max( CASE WHEN pm.meta_key = 'billing_first_name' and p.ID = pm.user_id THEN pm.meta_value END ) as Vorname,
        max( CASE WHEN pm.meta_key = 'billing_last_name' and p.ID = pm.user_id THEN pm.meta_value END ) as Nachname,
        max( CASE WHEN pm.meta_key = 'billing_phone' and p.ID = pm.user_id THEN pm.meta_value END ) as Telefon,
        max( CASE WHEN pm.meta_key = 'billing_postcode' and p.ID = pm.user_id THEN pm.meta_value END ) as PLZ,
        max( CASE WHEN pm.meta_key = 'billing_address_1' and p.ID = pm.user_id THEN pm.meta_value END ) as Strasse,     
        max( CASE WHEN pm.meta_key = 'billing_city' and p.ID = pm.user_id THEN pm.meta_value END ) as Ort,
        max( CASE WHEN pm.meta_key = 'kennung_produzent' and p.ID = pm.user_id THEN pm.meta_value END ) as Kennung

from
    wp_users p 
    join wp_usermeta pm on p.ID = pm.user_id
where  
    pm.meta_value = 'Prod'
group by
    p.ID

Answer 1

如果我理解正确，您只想将结果过滤为wp_usermeta中存在meta_key='kennung_produzent'和meta_value = 'Prod'行

该查询所做的是不同的，因为您正在按pm.meta_value = 'Prod'进行过滤，因此您要删除所有行，因为它还期望在pm.meta_key = 'billing_email'和pm.meta_key = 'nickname'时值是 Prod pm.meta_key = 'nickname'等等。

不知道您的数据，并且根据您的最后评论，假设每个用户有超过一行 meta_key="kennung_produzent"，我会说您想要做的更类似于

select * from (

SELECT p.ID,
       p.user_login,
       p.user_registered,
       p.display_name,
        max( CASE WHEN pm.meta_key = 'nickname' and p.ID = pm.user_id THEN pm.meta_value END ) as Nickname,
        max( CASE WHEN pm.meta_key = 'billing_email' and p.ID = pm.user_id THEN pm.meta_value END ) as email,
        max( CASE WHEN pm.meta_key = 'billing_first_name' THEN pm.meta_value END ) as Vorname,
        max( CASE WHEN pm.meta_key = 'billing_last_name' THEN pm.meta_value END ) as Nachname,
        max( CASE WHEN pm.meta_key = 'billing_phone' THEN pm.meta_value END ) as Telefon,
        max( CASE WHEN pm.meta_key = 'billing_postcode'  THEN pm.meta_value END ) as PLZ,
        max( CASE WHEN pm.meta_key = 'billing_address_1' THEN pm.meta_value END ) as Strasse,     
        max( CASE WHEN pm.meta_key = 'billing_city' THEN pm.meta_value END ) as Ort,
        max( CASE WHEN pm.meta_key = 'kennung_produzent' THEN pm.meta_value END ) as Kennung

from
    wp_users p 
    join wp_usermeta pm on p.ID = pm.user_id
group by
    p.ID

) a

where Kennung LIKE "Prod"

此查询的性能可能非常糟糕，但请让我知道它是否满足您的需求，因此至少我们有一个起点