小编Chr*_*sty的帖子

我有疑问打破了我网站的一个区域.尝试加载以下SQL语句时,该站点永远旋转!我是sql语句的新手,这个特定的语句是由另一个开发人员创建的.有没有办法优化以下声明？或者将其分解为较小的语句,以便更快地运行？我很茫然!我感谢任何帮助.

SELECT
    `wp_quiz_users`.`Id`,
    `wp_quiz_users`.`SessionId`,
    `wp_quiz_users`.`Score`,
    `wp_quiz_users`.`Date`,
    `wp_quiz_users`.`Referrer`,
    `wp_quiz_users`.`ContactData`,
    (SELECT
        SUM(`wp_quiz_users_answers`.`AnswerValue`) 
    FROM
        `wp_quiz_users_answers` 
    JOIN
        `wp_quiz_questions` 
            ON `wp_quiz_users_answers`.`QuestionId` = `wp_quiz_questions`.`id` 
    WHERE
        `wp_quiz_users_answers`.`UserId` = `wp_quiz_users`.`Id` 
        AND `wp_quiz_questions`.`Category` = 1) AS `SectionOne`,
    (SELECT
        SUM(`wp_quiz_users_answers`.`AnswerValue`) 
    FROM
        `wp_quiz_users_answers` 
    JOIN
        `wp_quiz_questions` 
            ON `wp_quiz_users_answers`.`QuestionId` = `wp_quiz_questions`.`id` 
    WHERE
        `wp_quiz_users_answers`.`UserId` = `wp_quiz_users`.`Id` 
        AND `wp_quiz_questions`.`Category` = 2) AS `SectionTwo`,
    (SELECT
        SUM(`wp_quiz_users_answers`.`AnswerValue`) 
    FROM
        `wp_quiz_users_answers` 
    JOIN
        `wp_quiz_questions` 
            ON `wp_quiz_users_answers`.`QuestionId` = `wp_quiz_questions`.`id` 
    WHERE
        `wp_quiz_users_answers`.`UserId` = `wp_quiz_users`.`Id` 
        AND `wp_quiz_questions`.`Category` = 3) AS `SectionThree`,
    (SELECT
        SUM(`wp_quiz_users_answers`.`AnswerValue`) 
    FROM
        `wp_quiz_users_answers` 
    JOIN
        `wp_quiz_questions` 
            ON `wp_quiz_users_answers`.`QuestionId` = `wp_quiz_questions`.`id` 
    WHERE
        `wp_quiz_users_answers`.`UserId` …