php - 如何解决执行查询时的数据库锁定问题

Question

嗨 friend 们谁能告诉我我的查询有什么问题。当我执行时，它会锁定数据库5到10分钟，请帮我优化这个查询。

SELECT 
    u.username, 
    u.email, 
    u.created_at, 
    p.firstname, 
    p.lastname, 
    p.address, 
    p.address_2, 
    p.city, 
    p.country, 
    p.state, 
    p.zip, 
    p.phone, 
    p.phone_2, 
    u.last_ip, 
    u.last_login_at, 
    u.auto_login, 
    u.registration_page,
    s.product_name
    FROM
    users AS u
        Left Join subscriptions AS s ON u.id = s.user_id
        Left Join profiles AS p ON u.id = p.user_id
    where u.registration_page='Chris_Cleanse' and
        u.id not in (select user_id from goal_sheets) and 
        u.id not in(select user_id from sheet_user_popup_not_adam) and 
        s.expired=TRUE ORDER BY u.id DESC;

Answer 1

我认为您的 where 条件中的子查询包含过多的数据。 也许你可以尝试像下面这样优化你的SQL:

SELECT
    u.username,u.email
    FROM
    users AS u
        Left Join subscriptions AS s ON u.id = s.user_id
        Left Join profiles AS p ON u.id = p.user_id
    Left Join goal_sheets gs ON u.id = gs.user_id
    Left Join sheet_user_popup_not_adam sa ON u.id = sa.user_id
    where u.registration_page='Chris_Cleanse' 
        and gs. user_id is null 
    and sa.user_id is null 
        s.expired=TRUE ORDER BY u.id DESC;