sql語句查詢時間比較
SELECT
e.id AS "id",
e.enterprise_name AS "enterpriseName",
y.industry_name AS "industryName",
d.district_name AS "districtName",
v.level_value AS "levelValue",
v.sumScore as "sumScore"
FROM
(
(
enterprise e
LEFT JOIN industry y ON e.industry_id = y.id
)
LEFT JOIN district d ON e.district_id = d.id
)
LEFT JOIN
(
SELECT i.enterprise_id,SUM(i.index_score) sumScore,l.level_value from index_enterprise_year i LEFT JOIN level_enterprise_year l ON i.enterprise_id = l.enterprise_id
AND l. YEAR = i.year where i.year=2017 GROUP BY i.enterprise_id
) v
ON e.id=v.enterprise_id
where
e.enterprise_status = 10
ORDER BY sumScore DESC
LIMIT 10
SELECT
e.id AS "id",
e.enterprise_name AS "enterpriseName",
e.business_registration_no AS "businessRegistrationNo",
e.organization_code AS "organizationCode",
e.unified_credit_code AS "unifiedCreditCode",
e.legal_person_name AS "legalPersonName",
e.enterprise_telephone AS "enterpriseTelephone",
e.registered_address AS "registeredAddress",
e.longitude AS "longitude",
e.dimension AS "dimension",
e.industry_id AS "industryId",
y.industry_name AS "industryName",
e.district_id AS "districtId",
d.district_name AS "districtName",
e.formula_id AS "formulaId",
e.enterprise_status AS "enterpriseStatus",
SUM(i.index_score) sumScore,
l.level_value
FROM
(
(
(
enterprise e
LEFT JOIN industry y ON e.industry_id = y.id
)
LEFT JOIN district d ON e.district_id = d.id
)
LEFT JOIN level_enterprise_year l ON e.id = l.enterprise_id
AND l. YEAR = 2017
)
LEFT JOIN index_enterprise_year i ON e.id = i.enterprise_id
AND i. YEAR = 2017
GROUP BY
e.id
HAVING
e.enterprise_status = 10
ORDER BY
sumScore DESC
LIMIT 10
兩條語句時間相差75倍,瞭解下原因