Hello，大家好！我是程序員阿飛！最近幾週一直在做統計相關的功能，因此，我分享幾個感覺比較好的SQL語句給大家，希望對大家能夠起到幫助以及學習的作用。
一、完整SQL
SELECT
e.org_id,
e.org_name,
CONVERT ( f.wgyCount, SIGNED ) wgyCount ,
CONVERT ( f.dayDurCount, SIGNED ) dayDurCount,
IFNULL( CAST( (( f.dayDurCount / f.wgyCount ) * 100 ) AS DECIMAL ( 8, 2 ) ), 0 ) dayDurPa***ate,
CONVERT ( f.dayLenCount, SIGNED ) dayLenCount,
IFNULL( CAST( (( f.dayLenCount / f.wgyCount ) * 100 ) AS DECIMAL ( 8, 2 ) ), 0 ) dayLenPa***ate
FROM
(
SELECT RIGHT
( sub_id, 36 ) id,
IFNULL( SUM( t.wgyCount ), '0' ) wgyCount ,
IFNULL( SUM( t.dayDurCount ), '0' ) dayDurCount ,
IFNULL( SUM( t.dayLenCount ), '0' ) dayLenCount
FROM
(
SELECT
wc.wgyCount,
ddc.dayDurCount,
dlc.dayLenCount,
ORG_NAME,
LEFT ( eoo.ORG_SEQ, ( SELECT 36 + CHAR_LENGTH( eo.ORG_SEQ ) FROM enterprise_org_object eo WHERE eo.ORG_ID = 'ec9525dc-d8a6-4608-b6b0-92be07721d78' ) ) sub_id
FROM
enterprise_org_object eoo
LEFT JOIN (
SELECT
eurc.org_id,
count( eurc.USER_Id ) wgyCount
FROM
enterprise_user_role_child eurc
WHERE
eurc.role_id = 8
GROUP BY
eurc.org_id
) wc ON wc.org_id = eoo.org_id
LEFT JOIN (
SELECT
eurc.ORG_ID orgId,
count( srd.childId ) dayDurCount
FROM
enterprise_user_role_child eurc
JOIN (
SELECT
csr.childId,
csr.locTime,
IFNULL( td.duration, '00:00:00' ) duration,
( CASE WHEN td.duration IS NULL THEN 0 ELSE ( TIME_TO_SEC( td.duration ) ) / 60 END ) changeTime
FROM
(
SELECT
sr.user_role_child_id childId,
sr.check_id checkId,
DATE_FORMAT( sr.location_time, '%Y-%m-%d' ) locTime
FROM
sign_record sr
RIGHT JOIN ( SELECT user_role_child_id, MAX( location_time ) AS "maxTime" FROM sign_record GROUP BY user_role_child_id ) tmp ON sr.location_time = tmp.maxTime
AND sr.user_role_child_id = tmp.user_role_child_id
WHERE
sr.user_role_child_id IS NOT NULL
) csr
LEFT JOIN (
SELECT
a.location_time locTime,
a.check_id checkId,
a.duration
FROM
trajectory_data AS a
LEFT JOIN ( SELECT MAX( location_time ) AS 'maxTime', check_id FROM trajectory_data GROUP BY check_id ) AS b ON a.check_id = b.check_id
WHERE
a.location_time = b.maxTime
) td ON td.checkId = csr.checkId
) srd ON eurc.ID = srd.childId
WHERE
eurc.ROLE_ID = 8
AND srd.changeTime > (SELECT ac.duration FROM assess_config ac WHERE ac.assess_type = '2' AND ac.del_flag = '0' )
AND srd.locTime = '2019-11-23'
GROUP BY
eurc.ID
) ddc ON ddc.orgId = eoo.org_id
LEFT JOIN (
SELECT
eurc.ORG_ID orgId,
count( srd.childId ) dayLenCount
FROM
enterprise_user_role_child eurc
JOIN (
SELECT
csr.childId,
csr.locTime,
IFNULL(td.length,'0.00') length
FROM
(
SELECT
sr.user_role_child_id childId,
sr.check_id checkId,
DATE_FORMAT( sr.location_time, '%Y-%m-%d' ) locTime
FROM
sign_record sr
RIGHT JOIN ( SELECT user_role_child_id, MAX( location_time ) AS "maxTime" FROM sign_record GROUP BY user_role_child_id ) tmp ON sr.location_time = tmp.maxTime
AND sr.user_role_child_id = tmp.user_role_child_id
WHERE
sr.user_role_child_id IS NOT NULL
) csr
LEFT JOIN (
SELECT
a.location_time locTime,
a.check_id checkId,
a.length
FROM
trajectory_data AS a
LEFT JOIN ( SELECT MAX( location_time ) AS 'maxTime', check_id FROM trajectory_data GROUP BY check_id ) AS b ON a.check_id = b.check_id
WHERE
a.location_time = b.maxTime
) td ON td.checkId = csr.checkId
) srd ON eurc.ID = srd.childId
WHERE
eurc.ROLE_ID = 8
AND srd.length > (SELECT ac.distance FROM assess_config ac WHERE ac.assess_type = '1' AND ac.del_flag = '0' )
AND srd.locTime = '2019-11-23'
GROUP BY
eurc.ID
) dlc ON dlc.orgId = eoo.org_id
) t
GROUP BY
sub_id
) f
LEFT JOIN enterprise_org_object e ON f.id = e.org_id
WHERE
e.ORG_SEQ LIKE '%ec9525dc-d8a6-4608-b6b0-92be07721d78%'
AND e.PARENT_ORG_ID = 'ec9525dc-d8a6-4608-b6b0-92be07721d78'
ORDER BY
e.ORG_ORDER
二、SQL分析
1、分組獲取最新的一條數據
SELECT
sr.user_role_child_id childId,
sr.check_id checkId,
DATE_FORMAT( sr.location_time, '%Y-%m-%d' ) locTime
FROM
sign_record sr
RIGHT JOIN ( SELECT user_role_child_id, MAX( location_time ) AS "maxTime" FROM sign_record GROUP BY user_role_child_id ) tmp ON sr.location_time = tmp.maxTime
AND sr.user_role_child_id = tmp.user_role_child_id
WHERE
sr.user_role_child_id IS NOT NULL
2、關聯子表獲取分組後的最新一條數據
SELECT
csr.childId,
csr.locTime,
IFNULL( td.duration, '00:00:00' ) duration,
( CASE WHEN td.duration IS NULL THEN 0 ELSE ( TIME_TO_SEC( td.duration ) ) / 60 END ) changeTime
FROM
(
SELECT
sr.user_role_child_id childId,
sr.check_id checkId,
DATE_FORMAT( sr.location_time, '%Y-%m-%d' ) locTime
FROM
sign_record sr
RIGHT JOIN ( SELECT user_role_child_id, MAX( location_time ) AS "maxTime" FROM sign_record GROUP BY user_role_child_id ) tmp ON sr.location_time = tmp.maxTime
AND sr.user_role_child_id = tmp.user_role_child_id
WHERE
sr.user_role_child_id IS NOT NULL
) csr
LEFT JOIN (
SELECT
a.location_time locTime,
a.check_id checkId,
a.duration
FROM
trajectory_data AS a
LEFT JOIN ( SELECT MAX( location_time ) AS 'maxTime', check_id FROM trajectory_data GROUP BY check_id ) AS b ON a.check_id = b.check_id
WHERE
a.location_time = b.maxTime
) td ON td.checkId = csr.checkId
三、SQL結果
cbdfec9f-1f8b-4fe0-8e21-eecf88317a0b 珠嶴鎮 86 0 0.00 0 0.00
7e199cbd-7c39-4e19-aa34-fa4cb2730eaa 海遊街道 76 0 0.00 0 0.00
8ce1d2a4-7f5d-49d9-b821-3353c8021f8f 海潤街道 34 0 0.00 0 0.00
dcef8d91-cff5-4590-9330-a070892414ad 橫渡鎮 26 0 0.00 0 0.00
3702bb74-a5c9-400d-a2dd-cebc9c452502 花橋鎮 35 0 0.00 0 0.00
fb8aabee-118e-405a-be8e-2a2cc251b18b 健跳鎮 76 0 0.00 0 0.00
1846d787-e9c8-4629-aaaa-fd5ace721955 蛇蟠鄉 6 0 0.00 0 0.00
f90b73c7-37fd-48d0-9100-c380d1d85ae0 沙柳街道 35 0 0.00 0 0.00
b656b49f-a155-4545-b0a7-30b41550bb14 浦壩港鎮 94 0 0.00 0 0.00
ea7a5dca-c933-49e3-b3ea-1274a290872e 亭旁鎮 112 1 0.89 1 0.89
6814b9eb-883e-4cd8-b981-fb98b8fc9e06 三門經濟開發區管委會 2 0 0.00 0 0.00
76947639-0fa6-48e9-9e68-007187e2a807 三門縣沿海工業城管理委員會 2 0 0.00 0 0.00
e6897d17-dc8c-4ced-b5cb-4b28f0c67a3a 絳帳鎮 3 0 0.00 0 0.00
四、SQL總結
1、CONVERT ( f.wgyCount, SIGNED ) 獲取該字段的整數部分，即將該字段值轉換成整數
2、IFNULL( SUM( t.dayLenCount ), '0' ) 如果該字段值不爲空，則取值，否則默認爲“0”
3、CAST( (( f.dayLenCount / f.wgyCount ) * 100 ) AS DECIMAL ( 8, 2 ) ) 求取兩個數的百分比值並保留兩位小數
4、TIME_TO_SEC( td.duration ) ) / 60 將時間類型的字段值轉換成分鐘
5、CASE WHEN td.duration IS NULL THEN 0 ELSE ( TIME_TO_SEC( td.duration ) ) / 60 END 如果某一字段值爲空時取0，否則取另一個值
6、DATE_FORMAT( sr.location_time, '%Y-%m-%d' ) locTime 將時間類型的字段值進行格式化轉化
7、CHAR_LENGTH( eo.ORG_SEQ ) 獲取某一字段的長度
8、LEFT ( eoo.ORG_SEQ , 108 ) sub_id 獲取某一字段中從左邊起前108位的字符串
9、RIGHT ( sub_id, 36 ) 獲取某一字段從右邊起36位的字符串