常用知识点：
===0、创建存储过程
create or replace procedure xxx_pro(pdate in date) is
ERR_MSG VARCHAR2(2000) := ''; --错误信息
begin
insert into xxx_LOG....
......
insert into xxx_LOG....
exception
when others then rollback;
ERR_MSG:=SQLERRM;
insert into xxx_LOG(id,Obj_Name,ATYPE,RESULT_MSG,ADD_TIME)values(seq_xxx_log.nextval,'xxx_pro',3,ERR_MSG,sysdate);
commit;
===1、游标 cursor
cursor info_cursor is --注释--
select id,name,...... from tb_xxx
begin
for d in info_cursor loop
if trunc(r.x)=trunc(pdate,'d') then
insert into xxx(id,.....) values(xxx,.....);
end if;
commit;
end loop;
===2、merge into table using() on xxx when matched then ..... when not matched then ...
merge into xxxx_tmp a using(
select xxxx,xxx
from xx
where trunc(xx)=pdate
group by gid,sid,gname
)b on(trunc(a.xx)=pdate and a.x=b.x and a.xx=b.xx)
when matched then
update set a.x=b.x ----更新到xxxx_tmp表
when not matched then
insert values(seq_xx.nextval,xx,........); ---插入到xxxx_tmp表
commit;
===3、 execute immediate
execute immediate('truncate table xxxx_tmp') ;--清空表，不管表是否存在，忽略报错
===4、INSERT INTO SELECT VS SELECT INTO FROM
1.INSERT INTO SELECT语句
语句形式为：Insert into Table2(field1,field2,...) select value1,value2,... from Table1
要求目标表Table2必须存在，由于目标表Table2已经存在，所以我们除了插入源表Table1的字段外，还可以插入常量。
2.SELECT INTO FROM语句
语句形式为：SELECT vale1, value2 into Table2 from Table1
要求目标表Table2不存在，因为在插入时会自动创建表Table2，并将Table1中指定字段数据复制到Table2中。