请教关于select里的join和on是什么意思?
请教关于select里的join和on是什么意思?
select e.*
from gln d join
pubobject b on d.gln=b.object_gln join
publication c on b.publication_id=c.publication_id join
iteminfo a on c.item_id=a.item_id join
tradeitem e on a.item_id=e.item_id
where d.f_id=5 and a.item_status='1' and e.valu like '%洗发水%'