我在我的穆迪网站上使用了下面给出的自定义查询，它的工作正常，但是现在mdl_user_enrollments表中的总记录为3000万，需要一些时间才能将结果返回到我的最终屏幕。请让我知道如何使其快速。
查询如下
select t1.userid,t2.courseid AS course_id, t1.timestart AS subscription_start, t1.timeend AS subscription_end,t1.timecreated AS timecreated,t1.timemodified AS timemodified, t3.id AS quiz_id,
t3.name AS quiz_name from mdl_user_enrolments t1
join mdl_enrol t2 on t1.userid=$user_id and t1.enrolid = t2.id
join mdl_quiz t3 on t3.course = t2.courseid
解释输出
Explain mdl_user_enrolments result
Field Type Null Key Default Extra
id bigint(10) NO PRI NULL auto_increment
status bigint(10) NO 0
enrolid bigint(10) NO MUL NULL
userid bigint(10) NO MUL NULL
timestart bigint(10) NO 0
timeend bigint(10) NO 2147483647
modifierid bigint(10) NO MUL 0
timecreated bigint(10) NO 0
timemodified bigint(10) NO 0
分析表mdl_user_enrolments结果
表操作Msg_type Msg_text
eLearningDev_v1.mdl_user_enrolments分析状态OK
表mdl_user_enrolments的大小910 MB
最佳答案
Select t1.userid,t2.courseid AS course_id, t1.timestart AS subscription_start, t1.timeend AS subscription_end,t1.timecreated AS timecreated,t1.timemodified AS timemodified, t3.id AS quiz_id,
t3.name AS quiz_name from mdl_user_enrolments t1
LEFT join mdl_enrol AS t2 on t1.userid=$user_id and t1.enrolid = t2.id
LEFT join mdl_quiz AS t3 on t3.course = t2.courseid
希望这对您有用。
关于php - PHP从3000万条记录中检索数据，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/41360154/