Question

求sqlserver自定义函数，比较三个数的大小，返回最大值

Answer 1

create function dbo.GetMax(@var1 int ,@var2 int ,@var3 int )
returns int
begin
declare @maxVar int;
if @var1 > @var2
set @maxVar = @var1;
else
set @maxVar = @var2;

if @maxVar > @var3
set @maxVar = @maxVar;
else
set @maxVar = @var3;

return @maxVar
end

Answer 2

select (case when a>b then a else b end ),
(case when b>c then b esle c end)
from table_name