How to insert records from table to another without duplicate

Question

I have two tables t1 and t2. t1 has duplicated values. I need to insert all records from t1 to t2, but I don\'t want duplicates to occur in t2. I tried the following command whi

Answer 1

I need to insert data from user to another user and when write this statement .....

insert into trep12.jobhead
select
*
from
wsfin04.jobhead
where
wsfin04.jobhead.job_no not in (select job_no from trep12.jobhead)
and wsfin04.jobhead.CHASS_NO not in (select CHASS_NO from trep12.jobhead)
and rdate between '01-jul-15'
and '01-oct-15'
and job_type = 1;

..... the result is 0 rows created.