需要帮助优化MySQL查询

Question

我有6张桌子：

CREATE TABLE IF NOT EXISTS `sbpr_groups` (
    `id` int(11) NOT NULL AUTO_INCREMENT, 
    `name` varchar(255) DEFAULT NULL, 
    `active` tinyint(1) DEFAULT '0', 
    `dnd` tinyint(1) DEFAULT '0', 
    PRIMARY KEY (`id`) 
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=32 ; 

CREATE TABLE IF NOT EXISTS `sbpr_newsletter` (
    `id` int(11) NOT NULL AUTO_INCREMENT, 
    `created_date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, 
    `from` varchar(255) COLLATE utf8_unicode_ci NOT NULL, 
    `mail` varchar(255) COLLATE utf8_unicode_ci NOT NULL, 
    `subject` varchar(255) COLLATE utf8_unicode_ci NOT NULL, 
    `body` text COLLATE utf8_unicode_ci, 
    `attach1` varchar(255) COLLATE utf8_unicode_ci NOT NULL, 
    `attach2` varchar(255) COLLATE utf8_unicode_ci NOT NULL, 
    `attach3` varchar(255) COLLATE utf8_unicode_ci NOT NULL, 
    PRIMARY KEY (`id`) 
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=14; 

CREATE TABLE IF NOT EXISTS `sbpr_news_groups` (
    `newsletter_id` int(11) NOT NULL, 
    `groups` int(11) NOT NULL, 
    KEY `fk_sbpr_news_groups_sbpr_newsletter1` (`newsletter_id`), 
    KEY `fk_sbpr_news_groups_sbpr_groups1` (`groups`) 
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; 

CREATE TABLE IF NOT EXISTS `sbpr_news_recs` (
    `newsletter_id` int(11) NOT NULL, 
    `recipients` int(11) NOT NULL, 
    KEY `fk_sbpr_news_recs_sbpr_newsletter1` (`newsletter_id`), 
    KEY `fk_sbpr_news_recs_sbpr_recipients1` (`recipients`) 
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; 

CREATE TABLE IF NOT EXISTS `sbpr_recipients` (
    `id` int(11) NOT NULL AUTO_INCREMENT, 
    `mail` varchar(160) DEFAULT NULL, 
    `date_reg` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, 
    `active` tinyint(1) DEFAULT '0', 
    PRIMARY KEY (`id`) 
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=3008 ; 

CREATE TABLE IF NOT EXISTS `sbpr_rec_groups` (
    `rec_id` int(11) NOT NULL, 
    `group` int(11) NOT NULL, 
    KEY `fk_sbpr_rec_groups_sbpr_recipients` (`rec_id`), 
    KEY `fk_sbpr_rec_groups_sbpr_groups1` (`group`) 
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin; 

有了这个foregin键：

ALTER TABLE `sbpr_news_groups` 
    ADD CONSTRAINT `fk_sbpr_news_groups_sbpr_groups1` 
    FOREIGN KEY (`groups`) REFERENCES `sbpr_groups` (`id`) 
    ON DELETE CASCADE ON UPDATE NO ACTION, 
    ADD CONSTRAINT `fk_sbpr_news_groups_sbpr_newsletter1` 
    FOREIGN KEY (`newsletter_id`) REFERENCES `sbpr_newsletter` (`id`) 
    ON DELETE CASCADE ON UPDATE NO ACTION; 

ALTER TABLE `sbpr_news_recs` 
    ADD CONSTRAINT `fk_sbpr_news_recs_sbpr_newsletter1` 
    FOREIGN KEY (`newsletter_id`) REFERENCES `sbpr_newsletter` (`id`) 
    ON DELETE CASCADE ON UPDATE NO ACTION, 
    ADD CONSTRAINT `fk_sbpr_news_recs_sbpr_recipients1` 
    FOREIGN KEY (`recipients`) REFERENCES `sbpr_recipients` (`id`) 
    ON DELETE CASCADE ON UPDATE NO ACTION; 

ALTER TABLE `sbpr_rec_groups` 
    ADD CONSTRAINT `fk_sbpr_rec_groups_sbpr_groups1` 
    FOREIGN KEY (`group`) REFERENCES `sbpr_groups` (`id`) 
    ON DELETE CASCADE ON UPDATE NO ACTION, 
    ADD CONSTRAINT `fk_sbpr_rec_groups_sbpr_recipients` 
    FOREIGN KEY (`rec_id`) REFERENCES `sbpr_recipients` (`id`) 
    ON DELETE CASCADE ON UPDATE NO ACTION; 

视觉表的结构：

我想选择所有的r OWS从sbpr_newsletter表，并从sbpr_recipients其id规定在sbpr_news_recs或规定在sbpr_rec_groups depence上FKS添加到每个这些行的行数的。

Ex。我想要选择所有收件人的通讯电子邮件都在sbpr_news_recs或存在于组中，至少在sbpr_rec_groups加上活跃收件人的数量。

我已经workinq SQL：

SELECT d.id, d.subject , d.created_date, 
    (SELECT count(*) FROM sbpr_recipients r 
     LEFT JOIN sbpr_news_recs nr ON nr.recipients = r.id 
     LEFT JOIN sbpr_rec_groups g ON g.rec_id = r.id 
     LEFT JOIN sbpr_news_groups ng ON ng.groups = g.group 
     WHERE nr.newsletter_id = d.id OR ng.newsletter_id = d.id) AS repicients, 

    (SELECT count(*) FROM sbpr_recipients r 
     LEFT JOIN sbpr_news_recs nr ON nr.recipients = r.id 
     LEFT JOIN sbpr_rec_groups g ON g.rec_id = r.id 
     LEFT JOIN sbpr_news_groups ng ON ng.groups = g.group 
     WHERE (nr.newsletter_id = d.id OR ng.newsletter_id = d.id) 
     AND r.active = 1) AS active_repicients 
FROM sbpr_newsletter d 
ORDER BY d.id ASC, d.id 

解释这个SQL语句： ​​

问题： 我如何优化SQL？

Answer 1

只是方法来优化，两个SELECT查询转移到JOIN子句 -

SELECT d.id 
    , d.subject 
    , d.created_date 
    , count(if(nr_newsletter_id is not null or ng_newsletter_id is not null, 1, null)) repicients 
    , count(if((nr_newsletter_id is not null or ng_newsletter_id is not null) and t.active = 1, 1, null)) active_repicients 
FROM 
    sbpr_newsletter d 
LEFT JOIN (
    SELECT nr.newsletter_id nr_newsletter_id 
     , ng.newsletter_id ng_newsletter_id 
     , r.active 
    FROM 
    sbpr_recipients r 
    LEFT JOIN sbpr_news_recs nr 
    ON nr.recipients = r.id 
    LEFT JOIN sbpr_rec_groups g 
    ON g.rec_id = r.id 
    LEFT JOIN sbpr_news_groups ng 
    ON ng.groups = g.group 
) t 
ON nr_newsletter_id = d.id OR ng_newsletter_id = d.id 
GROUP BY 
    d.id; 

我rewrited查询了一下，它不是测试，而是尝试。

Answer 2

你可以创建一个视图，查询代替 - 折衷是存储，但应该大大从服务器删除加载...

Answer 3

收件人的子查询/ active_recipients运行两次，每次返回3311条记录，所以它作为一种观点值得定义。

否则，请在连接中使用的外键上定义索引。