a的值有空格?
update table1
set colum1=(case ltrim(rtrim(a)) when '一' then '1' when '二' then '2' else '3' end)
where colum2=某个存在值
update table1
set colum1=(case ltrim(rtrim(a)) when '一' then '1' when '二' then '2' else '3' end)
where colum2=某个存在值
set colum1=(case when a='一' then '1' when a='二' then '2' else '3' end)
where colum2=某个存在值
select * from tb where cast(a as varchar) in ('一' , '二')看有没有数据?