Question

sql实现两表合并:A B表合成C表

Answer 1

select A.L1, A.L2, A.L3, B.L4

from 表A A Left outer join 表B B
on A.L1 = B.L1
Union

Select B.L1, B.L2, A.L3, B.L4

from 表B B Left Outer Join 表A A
on B.L1 = A.L1

Answer 2

select A.L1, A.L2, A.L3, B.L4

from 表A A Left outer join 表B B
on A.L1 = B.L1

Answer 3

select a.l1,a.l2,a.l3,null l4 from a
union
select b.l1,b.l3,null ,b.l4 from b

Answer 4

SELECT L1,L2,L3,L4 FROM A.a INNER JOIN B.b ON a.L1 = B.l1