sql server - How can I use select in null for an SSRS Report Parameter? -

i have ssrs report passes value stored procedure. in stored procedure, have following:

select * itemtable items in @itemvalues 

previously, work @itemvalues can multiple values between 1 5. however, null check has done how can null statement ?

you can use statement in procedure .

select * itemtable  @itemvalues null or items in @itemvalues