declare @T table (col varchar(8))
insert into @T
select '  a a a' union all
select 'bb b' union all
select ' cc c'

select * from @T
/*
col
--------
  a a a
bb b
 cc c
*/

update @T set col=ltrim(col)

select * from @T
/*
col
--------
a a a
bb b
cc c
*/

------解决方案--------------------
用ltrim()去掉最左边的空格