MySQL 查询在 phpMyAdmin 中运行正常，但在 PHP 中挂起

Question

我有一个相当简单的查询，当我在 phpMyAdmin 中测试它时运行没问题:

   SELECT   
        c.customers_id,
        c.customers_cid,
        c.customers_gender,
        c.customers_firstname,
        c.customers_lastname,
        c.customers_email_address,
        c.customers_telephone,
        c.customers_date_added,
        ab.entry_company,
        ab.entry_street_address,
        ab.entry_postcode, 
        ab.entry_city,
        COUNT(o.customers_id) AS orders_number,
        SUM(ot.value) AS totalvalue, 
        mb.bonus_points
   FROM     
        orders AS o,
        orders_total AS ot,
        customers AS c, 
        address_book AS ab, 
        module_bonus AS mb
   WHERE 
        c.customers_id = o.customers_id 
        AND c.customers_default_address_id = ab.address_book_id 
        AND c.customers_id = mb.customers_id    
        AND o.orders_id = ot.orders_id 
        AND ot.class = 'ot_subtotal'    
 **  AND c.customers_gender  = 'm' AND c.customers_lastname LIKE 'Famlex'
    GROUP BY o.customers_id

标有 ** 的行根据进行查询的应用程序的过滤设置而变化。

现在，当我在 phpMyAdmin 中对此进行测试时，查询需要几秒钟才能到达运行（这很好，因为有数千个条目，据我所知，在使用 COUNT 和SUM 索引没有帮助）并且结果是完美的，但是当我运行在 PHP 中完全相同的查询（在运行ning 之前回显）时，MySQL 线程加载一个核心到100%，直到我杀了它才停止。

如果我去除额外的东西来计算 COUNT 和 SUM，查询完成但结果对我没有用。

解释：

1   SIMPLE  mb  ALL     NULL                        NULL        NULL        NULL                                48713       Using temporary; Using filesort
1   SIMPLE  ot  ALL     idx_orders_total_orders_id  NULL        NULL        NULL                                811725      Using where
1   SIMPLE  o   eq_ref  PRIMARY                     PRIMARY     4           db.ot.orders_id                     1           Using where
1   SIMPLE  c   eq_ref  PRIMARY                     PRIMARY     4           db.o.customers_id                   1           Using where
1   SIMPLE  ab  eq_ref  PRIMARY                     PRIMARY     4           db.c.customers_default_address_id   1

EXPLAIN 在应用索引和使用连接后：

1   SIMPLE  c   ref     PRIMARY,search_str_idx              search_str_idx          98      const                                   1       Using where; Using temporary; Using filesort
1   SIMPLE  mb  ALL     NULL                                NULL                    NULL    NULL                                    48713   Using where
1   SIMPLE  ab  eq_ref  PRIMARY                             PRIMARY                 4       db.c.customers_default_address_id       1    
1   SIMPLE  ot  ref     idx_orders_total_orders_id,class    class                   98      const                                   157004  Using where
1   SIMPLE  o   eq_ref  PRIMARY                             PRIMARY                 4       db.ot.orders_id                         1       Using where

Answer 1

使用显式连接而不是隐式连接

SELECT  
c.customers_id,
c.customers_cid,
c.customers_gender,
c.customers_firstname,
c.customers_lastname,
c.customers_email_address,
c.customers_telephone,
c.customers_date_added,
ab.entry_company,
ab.entry_street_address,
ab.entry_postcode, 
ab.entry_city,
COUNT(o.customers_id) AS orders_number,
SUM(ot.value) AS totalvalue, 
mb.bonus_points
FROM    
orders o 
join orders_total ot on o.orders_id = ot.orders_id 
join customers c on c.customers_id = o.customers_id 
join address_book ab on c.customers_default_address_id = ab.address_book_id 
join module_bonus mb on c.customers_id = mb.customers_id 
where
ot.class = 'ot_subtotal'
c.customers_gender  = 'm' 
AND c.customers_lastname = 'Famlex'
GROUP BY o.customers_id

假设所有连接键也是这些表的主键，即：

o.orders_id, c.customers_id, ab.address_book_id

如果尚未添加以下索引，您将需要添加它们

alter table  orders add index customers_id_idx(customers_id);
alter table module_bonus add index customers_id_idx(customers_id);
alter table orders_total add index orders_id_idx(orders_id);
alter table orders_total add index orders_class_idx(class);
alter table customers add index search_str_idx(customers_gender,customers_lastname);

确保在应用索引之前对表进行备份。

Answer 2

能否分享 SQL 转储的记录，以便我查看？

phpMyAdmin 自动向 select 查询添加 limit 子句，这就是为什么我认为您认为在 phpMyAdmin 查询中运行很好但不是通过你 PHP 脚本。尝试在运行之前在 phpMyAdmin 中的查询中添加显式限制子句说 limit 0, 1000 ，看看这是否会使 phpMyAdmin 的性能变慢。

MySQL 查询在 phpMyAdmin 中运行正常，但在 PHP 中挂起

MySQL query runs ok in phpMyAdmin but hangs in PHP

php

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