mysql有什么方法可以加快查询速度

Question

我做了一个查询，它给了我需要的结果，但速度非常慢。

问题：非常慢。

问题：我有什么方法可以加快查询速度!!!

SELECT ci.ctt_region_id,
   ci.region_name,
   cs.slot_set_date,
   cs.ctt_photo_slot_id,
    /* Mon*/
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_set_time SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-12'
          AND slot_set_time = '11:00:00'
   ) as mon_eleven_time,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_set_time SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-12'
          AND slot_set_time = '14:00:00'
   ) as mon_two_time,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_set_time SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-12'
          AND slot_set_time = '17:00:00'
   ) as mon_five_time,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_count SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-12'
          AND slot_set_time = '11:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as mon_eleven_timecount,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_count SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-12'
          AND slot_set_time = '14:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as mon_two_timecount,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_count SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-12'
          AND slot_set_time = '17:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as mon_five_timecount,
    /* Tue*/
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_set_time SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-13'
          AND slot_set_time = '11:00:00'
   ) as tue_eleven_time,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_set_time SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-13'
          AND slot_set_time = '14:00:00'
   ) as tue_two_time,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_set_time SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-13'
          AND slot_set_time = '17:00:00'
   ) as tue_five_time,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_count SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-13'
          AND slot_set_time = '11:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as tue_eleven_timecount,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_count SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-13'
          AND slot_set_time = '14:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as tue_two_timecount,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_count SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-13'
          AND slot_set_time = '17:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as tue_five_timecount,
    /* Wed*/
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_set_time SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-14'
          AND slot_set_time = '11:00:00'
   ) as wen_eleven_time,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_set_time SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-14'
            AND slot_set_time = '14:00:00'
            AND ctt_region_id = ci.ctt_region_id
   ) as wen_two_time,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_set_time SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-14'
          AND slot_set_time = '17:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as wen_five_time,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_count SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-14'
          AND slot_set_time = '11:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as wen_eleven_timecount,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_count SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-14'
          AND slot_set_time = '14:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as wen_two_timecount,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_count SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-14'
          AND slot_set_time = '17:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as wen_five_timecount,
    /* Thu*/
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_set_time SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-15'
          AND slot_set_time = '11:00:00'
   ) as thu_eleven_time,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_set_time SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-15'
            AND slot_set_time = '14:00:00'
            AND ctt_region_id = ci.ctt_region_id
   ) as thu_two_time,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_set_time SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-15'
          AND slot_set_time = '17:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as thu_five_time,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_count SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-15'
          AND slot_set_time = '11:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as thu_eleven_timecount,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_count SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-15'
          AND slot_set_time = '14:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as thu_two_timecount,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_count SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-15'
          AND slot_set_time = '17:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as thu_five_timecount,
    /* Fri*/
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_set_time SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-16'
          AND slot_set_time = '11:00:00'
   ) as fri_eleven_time,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_set_time SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-16'
            AND slot_set_time = '14:00:00'
            AND ctt_region_id = cs.ctt_region_id
   ) as fri_two_time,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_set_time SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-16'
          AND slot_set_time = '17:00:00'
   ) as fri_five_time,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_count SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-16'
          AND slot_set_time = '11:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as fri_eleven_timecount,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_count SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-16'
          AND slot_set_time = '14:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as fri_two_timecount,
   (SELECT GROUP_CONCAT(DISTINCT AA.slot_count SEPARATOR ',')
     FROM ctt_photo_slot AA
    WHERE slot_set_date = '2015-01-16'
          AND slot_set_time = '17:00:00'
          AND ctt_region_id = ci.ctt_region_id
   ) as fri_five_timecount
   FROM ctt_photo_slot cs
   JOIN ctt_region ci
     ON cs.ctt_region_id = ci.ctt_region_id
   GROUP BY region_name;

Answer 1

使用条件聚合：

SELECT ci.ctt_region_id, ci.region_name, cs.slot_set_date, cs.ctt_photo_slot_id,
       /* Mon*/
       GROUP_CONCAT(DISTINCT CASE WHEN slot_set_date = '2015-01-12' AND slot_set_time = '11:00:00'
                                  THEN AA.slot_set_time END SEPARATOR ',') as mon_eleven_time,
       GROUP_CONCAT(DISTINCT CASE WHEN slot_set_date = '2015-01-12' AND slot_set_time = '14:00:00'
                                  THEN AA.slot_set_time END SEPARATOR ',') as mon_two_time,
       . . . 
FROM ctt_photo_slot cs JOIN
     ctt_region ci
     ON cs.ctt_region_id = ci.ctt_region_id
GROUP BY region_name;

目前尚不清楚cs.slot_set_date中cs.ctt_photo_slot_id和select正在做什么。 group by为每个区域生成一行，因此如果有多个值，则选择任意值。