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POJoin Nearest Date
 

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  1. POJoin Nearest Date
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    <p>I have read through a ton of responses on here but nothing is working quite as well as I would like. I currently have a working query that includes 2 sub queries, the problem is that it takes about 10 seconds to execute. I was wondering if there is any way to make this go quicker, maybe with a join. I just can't seem to get my head out of the box it is in. Please let me know your thoughts.</p> <p>Here is the working query:</p> <pre><code>Select concat(a.emp_firstname, ' ', a.emp_lastname) as names , if(if (a.emp_gender = 1, 'Male', a.emp_gender)=2, 'Female', if (a.emp_gender = 1, 'Male', a.emp_gender)) as emp_gender , c.name , a.emp_work_telephone , a.emp_hm_telephone, a.emp_work_email , a.custom7, a.employee_id , a.city_code, a.provin_code, d.name as status, (SELECT cast(concat(DATE_FORMAT(e.app_datetime, '%H:%i'), ' ', e.app_facility) as char(100)) FROM li_appointments.li_appointments as e where e.terp_id = a.employee_id and e.app_datetime &lt;= str_to_date('06/26/13 at 3:20 PM', '%m/%d/%Y at %h:%i %p') and date(e.app_datetime) = date(str_to_date('06/26/13 at 3:20 PM', '%m/%d/%Y at %h:%i %p')) order by e.app_datetime desc limit 1) as prevapp, (SELECT cast(concat(DATE_FORMAT(e.app_datetime, '%H:%i'), ' ', e.app_facility) as char(100)) FROM li_appointments.li_appointments as e where e.terp_id = a.employee_id and e.app_datetime &gt; str_to_date('06/26/13 at 3:20 PM', '%m/%d/%Y at %h:%i %p') and date(e.app_datetime) = date(str_to_date('06/26/13 at 3:20 PM', '%m/%d/%Y at %h:%i %p')) order by e.app_datetime desc limit 1) as nextapp from hs_hr_employee as a Join hs_hr_emp_skill as b on a.emp_number = b.emp_number Join ohrm_skill as c on b.skill_id = c.id Join orangehrm_li.ohrm_employment_status as d on a.emp_status = d.id where c.name like '%Arabic%' and d.name = 'Active' order by rand(); </code></pre> <p><code>EXPLAIN</code> results:</p> <pre> +----+--------------------+-------+--------+---------------------+------------+---------+---------------------------+-------+----------------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+--------------------+-------+--------+---------------------+------------+---------+---------------------------+-------+----------------------------------------------+ | 1 | PRIMARY | d | ALL | PRIMARY | | | | 10 | Using where; Using temporary; Using filesort | | 1 | PRIMARY | a | ref | PRIMARY,emp_status | emp_status | 5 | orangehrm_li.d.id | 48 | Using where | | 1 | PRIMARY | b | ref | emp_number,skill_id | emp_number | 4 | orangehrm_li.a.emp_number | 1 | | | 1 | PRIMARY | c | eq_ref | PRIMARY | PRIMARY | 4 | orangehrm_li.b.skill_id | 1 | Using where | | 3 | DEPENDENT SUBQUERY | e | ALL | | | | | 28165 | Using where; Using filesort | | 2 | DEPENDENT SUBQUERY | e | ALL | | | | | 28165 | Using where; Using filesort | +----+--------------------+-------+--------+---------------------+------------+---------+---------------------------+-------+----------------------------------------------+ </pre>
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    1. PTQuestion
    1. USG-Nugget
    1. USRene Gomez
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    1. VO
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      1. POJoin Nearest Date
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
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      1. VTUpMod
    1. COTo look a bit deeper, please post the output of `EXPLAIN SELECT (yourquery)`.
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      1. USBjoern
    2. COWhat happens if you remove your order by rand()? While I can see how it may be useful, it is probably bringing your database to it's knees if your record selection is large.
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      1. USJoe Meyer
    3. COJoe, the results are usually around 20 - 30 rows. In my testing the rand() does not seem to be the problem. When I remove the sub querires the total duration is less than .02 secconds.
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      1. USRene Gomez
 

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