多表查詢新增索引

共有t_member（成員表）t_organization（單位表）t_member_t_organization（成員單位對映表）

select 語句如下

select tm.id,tm.name,birth,

case ***
when '1' then '男'
when '2' then '女'
else '其他' end as ***,
is_admin as isadmin,
username,password,
duty,qualification,political,email,
tor.name as organization,
is_manager as ismanager,
level,tm.performance,tm.dues,area,company,
job_title as jobtitle,
id_number as idnumber,telephone,qq,photo,grade,item,
grade_date as gradedate,
grade_num as  gradenum,
instructed_date as instructeddate,
instructed_num as instructednum,
instructed_item as instructeditem,
managed_date as manageddate,
managed_num as managednum,
managed_item as manageditem,
examed_date as exameddate,
examed_num as examednum,
examed_item as exameditem,
is_judge as isjudge,
judge_number as judgenumber,
judge_date as judgedate,
is_coach as iscoach,
coach_date as coachdate,
coach_number as coachnumber,
is_instructor as isinstructor,
instructor_date as instructordate,
instructor_number as instructornumber,
experience,
activity,tm.status
from  t_member  tm
left join t_member_organization tmo on tm.id = tmo.member_id
left join t_organization tor on tmo.organization_id = tor.id

然後我們試試在對映表上加上索引後

檢視下這時候的資料庫查詢速度

僅僅有0.1秒~ 

這優化效果不錯吧··

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