how to create query based on optional field on temp table ?

Question

problem

how to create query based on optional field on temp table ?

I work on sql server 2012

I have temp table #tempsupplier have two fields

SupplierId mandatory have value

TradeCode optinal have value may be have or may be not have value

so i need

 

if(tradecode have value then execute)

do specific select

select p.PartID, p.PartNumber,m.SupplierId,m.TradeCode from #tempsupplier m
inner join #parts p   on p.SupplierId=m.SupplierId
where not exists ( select 1 from  #TradeCodes t where t.TradeCode=m.TradeCode)

if (tradecode not have value meaning is null then execute depend on supplier only)

select p.PartID, p.PartNumber,m.SupplierId,m.TradeCode from #tempsupplier m
inner join #parts p   on p.SupplierId=m.SupplierId
where not exists ( select 1 from  #TradeCodes t where t.PartID=p.PartID )

 

details data as below

create table #tempsupplier
(
SupplierId  int,
TradeCode  int
)
insert into #tempsupplier(SupplierId,TradeCode)
values
(10,15),
(11,null)

create table #parts
(
PartID  int,
PartNumber  nvarchar(200),
SupplierId int,
TradeCode int
)

insert into #parts
(PartID,PartNumber,SupplierId)
values
(100,'silicon',10),
(200,'motherboard',10),
(300,'iron',10),
(400,'plastic',10),
(500,'Car',11),
(600,'Bicycle',11),
(700,'plan',11)


create table #TradeCodes
(
PartID int,
TradeCode int
)
insert into #TradeCodes
(PartID,TradeCode)
values
(300,10),
(400,10),
(500,20)