select FCY,BNAM,BNUM,ITMDES,ITMNUM,sum(FQTY) FQTY,sum(TQTY) TQTY from 
(select FCY,BNAM,BNUM,ITMDES,ITMNUM,FQTY,TQTY=convert(float,0) from 表1
union all select FCY,BNAM,BNUM,ITMDES,ITMNUM,0,TQTY from 表2) t
group by FCY,BNAM,BNUM,ITMDES,ITMNUM;

------解决方案--------------------

SQL code
if object_id(N'[表1]') is not null drop table [表1]
go
create table [表1](FCY varchar(10),BNAM varchar(10), BNUM varchar(10), ITMDES varchar(10), ITMNUM varchar(10), FQTY int)
go
insert into [表1]
select 'A01', 'AAA', 'A001', 'AXXXX', '100111', 23 union all
select 'A01', 'AAA', 'A001', 'BXXXX', '200111', 50
go
if object_id(N'[表2]') is not null drop table [表2]
go
create table [表2](FCY varchar(10),BNAM varchar(10), BNUM varchar(10), ITMDES varchar(10), ITMNUM varchar(10), TQTY int)
go
insert into [表2]
select 'A01', 'AAA', 'A001', 'BXXXX', '200111', 25 union all
select 'A01', 'AAA', 'A001', 'CXXXX', '300111', 80
go

select FCY, BNAM, BNUM, ITMDES, ITMNUM,sum(FQTY) FQTY,sum(TQTY) TQTY 
from
(
    select FCY, BNAM, BNUM, ITMDES, ITMNUM,FQTY,0 as TQTY from [表1] 
    union all
    select FCY, BNAM, BNUM, ITMDES, ITMNUM,0 as FQTY,TQTY from [表2] 
) t
group by FCY, BNAM, BNUM, ITMDES, ITMNUM

/*

(2 row(s) affected)

(2 row(s) affected)
FCY        BNAM       BNUM       ITMDES     ITMNUM     FQTY        TQTY
---------- ---------- ---------- ---------- ---------- ----------- -----------
A01        AAA        A001       AXXXX      100111     23          0
A01        AAA        A001       BXXXX      200111     50          25
A01        AAA        A001       CXXXX      300111     0           80

(3 row(s) affected)


*/