我正在greenplum做某事:
insert into hctest.tab1
select
a::bytea,
b::varchar,
c::varchar
from hctest.ext_city2;
表选项卡1中的现有值:
id | name | address
-------+-----------+-----------
10011 | John | Serang
10012 | Calvin | Tangerang
10013 | Layla | Jakarta
表ext_city2中的值:
a | b | c
-------+-----------+-----------
10011 | John | Serang
10012 | Calvin | Tangerang
10013 | Layla | Jakarta
10014 | Kevin | Bandung
10015 | Rudy | Bali
如果我将所有数据从ext_city2
加载到tab1
,则会出现重复的行。我只想将不重复的行加载到tab1
。我该怎么办?
尝试一下:
insert into hctest.tab1
(
select * from hctest.ext_city2 ec where not exists
(select * from hctest.tab1 tb where ec.id=tb.a)
);