这样的效率更高:if @aa=1 select ...... where field1 like 'a%' else select ...... where field1 not like 'a%'
--或者: where case @aa when 1 then case when field1 like 'a%' then 1 else 0 end when 2 then case when field1 like 'b%' then 1 else 0 end else case when field1 like 'c%' then 1 else 0 end end=1
select * from yourtable where field1 like (case @aa when 1 then 'a%' when 2 then '[^a]%' end)
这样的效率更高:if @aa=1
select ...... where field1 like 'a%'
else
select ...... where field1 not like 'a%'
where case @aa
when 1 then case when field1 like 'a%' then 1 else 0 end
when 2 then case when field1 like 'b%' then 1 else 0 end
else case when field1 like 'c%' then 1 else 0 end end=1