INSERT: 批量插入结果集方式

INSERT: 批量插入结果集

1. insert into table
   select x,y from A
   UNION select z,k from B ;
2. insert into table
   select x,y,z from A where 1=1;
   3.批量导入表数据 ，不导入表约束
   select x,y,z into B from A where 1=1;