0

このクエリに問題があります:

SELECT Group_concat(DISTINCT titlegredcd) 
       targetGroup, 
       tblevent.id, 
       generalsubcategorynm, 
       generalcategorynm, 
       coursename, 
       (SELECT Count(*) 
        FROM   tblinternalstudent, 
               tblstaff 
        WHERE  eventid = tblevent.id 
               AND tblinternalstudent.staffnoic = tblstaff.staffnoic) Total, 
       Date_format(startdate, '%d %b') 
       startdateDisplay, 
       Date_format(enddate, '%d %b') 
       enddateDisplay, 
       class, 
       organizer, 
       subcategorymainorder, 
       subcategorysuborder, 
       tblrefgeneralsubcategory.generalcategorycd, 
       tblrefgeneralsubcategory.generalsubcategorycd 
FROM   tblevent, 
       tblcourse, 
       tblrefgeneralsubcategory, 
       tblrefgeneralcategory, 
       tblinternalstudent a, 
       tblstaff b 
WHERE  tblrefgeneralsubcategory.generalcategorycd IN 
       ( 'G0001', 'G0002', 'G0003' ) 
       AND tblcourse.generalcategorycd = 
           tblrefgeneralsubcategory.generalcategorycd 
       AND tblcourse.generalsubcategorycd = 
           tblrefgeneralsubcategory.generalsubcategorycd 
       AND tblevent.courseid = tblcourse.courseid 
       AND tblrefgeneralsubcategory.generalcategorycd = 
           tblrefgeneralcategory.generalcategorycd 
       AND a.eventid = tblevent.id 
       AND a.staffnoic = b.staffnoic 
       AND startdate >= '2012-01-01' 
       AND enddate <= '2012-12-31' 
GROUP  BY tblevent.id, 
          generalsubcategorynm, 
          generalcategorynm, 
          coursename, 
          total, 
          startdatedisplay, 
          enddatedisplay, 
          class, 
          organizer, 
          subcategorymainorder, 
          subcategorysuborder, 
          tblrefgeneralsubcategory.generalcategorycd, 
          tblrefgeneralsubcategory.generalsubcategorycd 
ORDER  BY tblrefgeneralsubcategory.generalsubcategorycd, 
          coursename

処理に約 30 分かかりますが、問題はサブセレクトにあると思われます。

join を使用して書き直そうとします:

SELECT e.id, 
       e.courseid, 
       internalstaff.targetgroup, 
       internalstaff.total, 
       Date_format(startdate, '%d %b') AS startdateDisplay, 
       Date_format(enddate, '%d %b')   AS enddateDisplay, 
       class, 
       organizer, 
       coursename, 
       gs.generalcategorycd, 
       gs.generalsubcategorycd, 
       gs.generalsubcategorynm, 
       gs.subcategorymainorder, 
       gs.subcategorysuborder, 
       generalcategorynm 
FROM   tblcourse c, 
       tblrefgeneralsubcategory gs, 
       tblrefgeneralcategory g, 
       tblevent e 
       JOIN (SELECT i.eventid, 
                    Count(*)                           AS Total, 
                    Group_concat(DISTINCT titlegredcd) AS TargetGroup 
             FROM   tblinternalstudent i, 
                    tblstaff s 
             WHERE  i.staffnoic = s.staffnoic 
             GROUP  BY i.eventid) AS internalstaff 
         ON internalstaff.eventid = e.id 
WHERE  e.courseid = c.courseid 
       AND gs.generalcategorycd = g.generalcategorycd 
       AND gs.generalcategorycd IN ( 'G0001', 'G0002', 'G0003' ) 
       AND c.generalcategorycd = gs.generalcategorycd 
       AND c.generalsubcategorycd = gs.generalsubcategorycd 
       AND startdate >= '2012-01-01' 
       AND enddate <= '2012-12-31' 
GROUP  BY e.id, 
          generalsubcategorynm, 
          generalcategorynm, 
          startdatedisplay, 
          enddatedisplay, 
          class, 
          organizer, 
          subcategorymainorder, 
          subcategorysuborder, 
          generalcategorycd, 
          generalsubcategorycd 
ORDER  BY generalsubcategorycd, 
          coursename

読み込みが速くなり、元のクエリ (1802) と同じ数のレコードが返されます。ただし、BranchCd (および branchcd = 'some branch code') を internalstaff テーブルに追加すると、返されるレコードの数が少なくなります (519)。

ただし、元のクエリでは、(and branchcd = 'some branch code') がサブ選択に追加されると、正しい数のレコードが返されます。

サブセレクトのように動作するように結合を書き直す方法について誰かアドバイスをいただけますか?

ありがとうございました。

編集済み:テーブルを含めるのを忘れて申し訳ありません:

tblinternalstudent (**staffnoic**, eventid)
tblstaff (**staffnoic** titlegredcd, branchcd, unitcd)
tblevent (**id**, courseid, startdate, enddate, class, organizer)
tblcourse (**courseid**, coursename)
tblrefgeneralcategory (**generalcategorycd**, generalcategorynm)
tblrefgeneralsubcategory (**generalsubcategorycd, generalsubcategorynm, generalcategorycd,subcategorymainorder, subcategorysuborder)

元のクエリの EXPLAIN:

*************************** 1. row ***************************
       id: 1
       select_type: PRIMARY
       table: a
       type: ALL
       possible_keys: NULL
       key: NULL
       key_len: NULL
       ref: NULL
       rows: 38760
       Extra: Using temporary; Using filesort
*************************** 2. row ***************************
       id: 1
       select_type: PRIMARY
       table: b
       type: eq_ref
       possible_keys: PRIMARY
       key: PRIMARY
       key_len: 44
       ref: edu_db.a.StaffNoIC
       rows: 1
       Extra: Using where
*************************** 3. row ***************************
       id: 1
       select_type: PRIMARY
       table: tblEvent
       type: eq_ref
       possible_keys: PRIMARY
       key: PRIMARY
       key_len: 32
       ref: edu_db.a.EventId
       rows: 1
       Extra: Using where
*************************** 4. row ***************************
       id: 1
       select_type: PRIMARY
       table: tblcourse
       type: eq_ref
       possible_keys: PRIMARY
       key: PRIMARY
       key_len: 30
       ref: edu_db.tblEvent.courseid
       rows: 1
       Extra: Using where
*************************** 5. row ***************************
       id: 1
       select_type: PRIMARY
       table: tblRefGeneralSubCategory
       type: eq_ref
       possible_keys: PRIMARY
       key: PRIMARY
       key_len: 34
       ref: edu_db.tblcourse.GeneralSubCategoryCd,edu_db.tblcourse.GeneralCategoryCd
       rows: 1
       Extra:
*************************** 6. row ***************************
       id: 1
       select_type: PRIMARY
       table: tblRefGeneralCategory
       type: eq_ref
       possible_keys: PRIMARY
       key: PRIMARY
       key_len: 17
       ref: edu_db.tblcourse.GeneralCategoryCd
       rows: 1
       Extra:
*************************** 7. row ***************************
       id: 2
       select_type: DEPENDENT SUBQUERY
       table: tblinternalstudent
       type: ALL
       possible_keys: NULL
       key: NULL
       key_len: NULL
       ref: NULL
       rows: 38760
       Extra: Using where
*************************** 8. row ***************************
       id: 2
       select_type: DEPENDENT SUBQUERY
       table: tblStaff
       type: eq_ref
       possible_keys: PRIMARY
       key: PRIMARY
       key_len: 44
       ref: edu_db.tblinternalstudent.StaffNoIC
       rows: 1
       Extra: Using where; Using index

2 番目のクエリの EXPLAIN:

*************************** 1. row ***************************
       id: 1
       select_type: PRIMARY
       table: <derived2>
       type: ALL
       possible_keys: NULL
       key: NULL
       key_len: NULL
       ref: NULL
       rows: 8849
      Extra: Using temporary; Using filesort
*************************** 2. row ***************************
       id: 1
       select_type: PRIMARY
       table: e
       type: eq_ref
       possible_keys: PRIMARY
       key: PRIMARY
       key_len: 32
       ref: internalstaff.eventid
       rows: 1
      Extra: Using where
*************************** 3. row ***************************
       id: 1
       select_type: PRIMARY
       table: c
       type: eq_ref
       possible_keys: PRIMARY
       key: PRIMARY
       key_len: 30
       ref: edu_db.e.courseid
       rows: 1
       Extra: Using where
*************************** 4. row ***************************
       id: 1
       select_type: PRIMARY
       table: gs
       type: eq_ref
       possible_keys: PRIMARY
       key: PRIMARY
       key_len: 34
       ref: edu_db.c.GeneralSubCategoryCd,edu_db.c.GeneralCategor
       rows: 1
       Extra:
*************************** 5. row ***************************
       id: 1
       select_type: PRIMARY
       table: g
       type: eq_ref
       possible_keys: PRIMARY
       key: PRIMARY
       key_len: 17
       ref: edu_db.gs.GeneralCategoryCd
       rows: 1
       Extra: Using where
*************************** 6. row ***************************
       id: 2
       select_type: DERIVED
       table: i
       type: ALL
       possible_keys: NULL
       key: NULL
       key_len: NULL
       ref: NULL
       rows: 38760
       Extra: Using filesort
*************************** 7. row ***************************
       id: 2
       select_type: DERIVED
       table: s
       type: eq_ref
       possible_keys: PRIMARY
       key: PRIMARY
       key_len: 44
       ref: edu_db.i.StaffNoIC
       rows: 1
4

1 に答える 1

0

ここで明確に伝えていないため、このクエリを試してください。関係の問題がある可能性もあります。

SELECT
  te.id,
  Date_format(startdate, '%d %b') AS startdateDisplay,
  Date_format(enddate, '%d %b') AS enddateDisplay,
  te.class,
  te.organizer,
  tgs.generalcategorycd,
  tgs.generalsubcategorycd,
  tgs.generalsubcategorynm,
  tgs.subcategorymainorder,
  tgs.subcategorysuborder,
  trc.generalcategorynm,
  count(tic.*)             AS `Total`,
  GROUP_CONCAT(DISTINCT tic. titlegredcd) AS TargetGroup
FROM tblevent AS te
  LEFT JOIN tblinternalstudent AS tis
    ON tis.eventid = te.id
  LEFT JOIN tblstaff AS ts
    ON ts.staffnoic = tis.staffnoic
  LEFT JOIN tblcourse AS tc
    ON tc.courseid = te.courseid
  LEFT JOIN tblrefgeneralsubcategory AS tgs
    ON tgs.generalcategorycd = tc.generalcategorycd
  LEFT JOIN tblrefgeneralcategory AS trc
    ON trc.generalcategorycd = tgs.generalcategorycd
WHERE te.startdate >= '2012-01-01'
    AND te.enddate <= '2012-12-31'
    AND trc.generalcategorycd IN('G0001', 'G0002', 'G0003')
GROUP BY te.id, tgs.generalsubcategorynm, trc.generalcategorynm, te.startdatedisplay, te.enddatedisplay te.class, te.organizer, tgs.subcategorymainorder, tgs.subcategorysuborder, trc.generalcategorycd, tgs.generalsubcategorycd
ORDER BY tgs.generalsubcategorycd, tc.coursename
于 2013-03-04T17:30:05.803 に答える