Oracle 数据库删除完全重复数据

Oracle Minus 关键字
SQL中的MINUS关键字
SQL中有一个MINUS关键字，它运用在两个SQL语句上，简单来说，就是找到第一个SQL语句的结果中有且
第二个SQL语句结果中没有的记录，其语法如下：
[SQL Segment 1]
MINUS
[SQL Segment 2]

删除完全重复记录
delete from sendbill_header where rowid in
        (select rowid from sendbill_header
        minus
        select max(rowid) from sendbill_header
        group by no,filename);
       
delete from sendbill_lines where rowid in
        (select rowid from sendbill_lines
        minus
        select max(rowid) from sendbill_lines
        group by  headerno,mtlno,version,qty);

可以体会下minus的作用，对比union
create table A(
    a   number
);
create table B(
    b   number
);
insert into a values(1);
insert into a values(2);
insert into a values(3);
insert into a values(4);
insert into a values(5);
insert into b values(4);
insert into b values(5);
insert into b values(6);
insert into b values(7);
insert into b values(8);
select * from a;
select * from b;
select * from a minus select * from b;
select * from b minus select * from a;
select * from a union select * from b;