Joining two tables Using UNION

two tables

//No Error

select Fname,Lname from tbl_Master

union

select Fname,Lname from tbl_Master

Two proc

//Error

exec SPtbl_Master1

union

exec SPtbl_Master2

Two Table-valued Functions

//No Error

select * from Fntbl_Master1('p')

union

select * from Fntbl_Master2('p')