插入表没有交叉部分

Question

如果我有两个SQL表，table_a和table_b，两者都是相同的，除了它们可能包含不同的数据，我想在table_b中插入table_b中不存在的所有行，如何查询看起来像 ？这些表仅包含id1和id2列。 如果我的问题不明确，请告诉我

Insert into table_a ...

谢谢

Answer 1

; with cte_left as
(
select id1+id2
from table_a
where id1+id2 not in (select id1+id2 from table_b)
)

insert into table_b
select * from cte_left

Answer 2

您可以使用EXCEPT运算符：

INSERT INTO table_a (id1, id2)
SELECT id1, id2
FROM (
  SELECT id1, id2
  FROM table_b

  EXCEPT

  SELECT id1, id2
  FROM table_a
) except_gry

SQL小提琴演示here

Answer 3

Insert into table_a ( id1, id2 ) 
select b.id1, b.id2
from table_b b
left outer join table_a a on a.id1 = b.id1 and a.id2 = b.id2
where a.id1 is null

Answer 4

您的查询中不存在：

insert into table_a(id1,id2)
select id1,id2 
from table_b 
where not exists(select id1,id2 from table_a)