sql语句查询时间的方式比较（代码实例）
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
两条语句时间相差75倍,了解下原因