如何從 wordpress 表中獲取 SQL 查詢

Question

我有一個 sql 查詢，但沒有找到正確的解決方案。

查詢有效，但它沒有顯示wp_usermeta表的列，只顯示wp_users的列。

如果我刪除where子句，將顯示所有列的所有值的行，但我只需要取決於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

如果我理解正確，您只想將結果過濾為wp_usermeta中存在meta_key='kennung_produzent'和meta_value = 'Prod'行

該查詢所做的是不同的，因為您正在按pm.meta_value = 'Prod'進行過濾，因此您要刪除所有行，因為它還期望在pm.meta_key = 'billing_email'和pm.meta_key = 'nickname'時值是 Prod pm.meta_key = 'nickname'等等。

不知道您的數據，並且根據您的最后評論，假設每個用戶有超過一行 meta_key="kennung_produzent"，我會說您想要做的更類似於

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"

此查詢的性能可能非常糟糕，但請讓我知道它是否滿足您的需求，因此至少我們有一個起點