SQL中怎么比较两个表中两列的数据值是否相同 然后把计较结果作为新列显示

[H_nufei]

具体说明：A,B两个表都有‘name’列，A表匹配在B表中是否值相等，并将结果在A表中新增一列显示，大概如图

[belsai]

select name,case n when 1 then 0 else 1 end as upd from
(select name,sum(n) as n from
(select name,1 as n from a_table
union all
select name,1 as n from b_table) t
group by name) t

[心有微凉何处雨]

你说的应该是显示A表中哪些人在B表存在，新增一列1表示存在，0表示不存在吧？其实用left join 就可以解决

select A.name, ISNULL(B1.FExists,0) 
from A left join (select name,1 AS FExists from B) B1 ON A.name = B1.name

[吉普赛的歌]

SELECT A.name,
       CASE 
            WHEN B.name IS NULL THEN 0
            ELSE 1
       END AS [更新列]
FROM   A
       LEFT JOIN B
            ON  A.name = B.name