01)
select id from sale_Invoice
where invoiceDate <= @OnDate
and invoiceDate >= isnull(@OBDate,invoiceDate)
02)
select id from sale_Invoice
where invoiceDate<=@OnDate
and invoiceDate >= case when @OBDate is null then invoiceDate else @OBDate end
03)
declare @sql nvarchar(100),
@sql1 nvarchar(100),
@sql2 nvarchar(100)
set @sql1 = 'select id from sale_Invoice
where invoiceDate <= '+ @OnDate
set @sql2 = 'and invoiceDate >= '+@OBDate
if @OBDate is null
begin
set @sql = @sql1
exec sp_executesql @sql
end
else
begin
set @sql = @sql1+@sql2
exec sp_executesql @sql
end