1.插入的数据来源自其他表
insert into A(id,cola) select id,cola from B where colb>1000
2.插入时排除(忽略)重复记录
insert ignore into A(id,cola) select id,cola from B where colb>1000
3.插入时遇到重复记录做更新操作
insert into A(id,cola) select id,cola from C on duplicate key update A.cola=C.cola