Sql 获取每个产品上每个员工的费率

我有三张桌子

a有

b有

c是空的，并且有列

empId(fk) | prodID(fk) | rate

如何得到以下结果

empID | prodName | rate 
------+----------+------
   1  | apple    | 0.00
   1  | banana   | 0.00
   1  | cherry   | 0.00
   2  | apple    | 0.00
   2  | banana   | 0.00
   2  | cherry   | 0.00
   3  | apple    | 0.00
   3  | banana   | 0.00
   3  | cherry   | 0.00

empId(fk) | prodID(fk) | rate

empID | prodName | rate 
------+----------+------
   1  | apple    | 0.00
   1  | banana   | 0.00
   1  | cherry   | 0.00
   2  | apple    | 0.00
   2  | banana   | 0.00
   2  | cherry   | 0.00
   3  | apple    | 0.00
   3  | banana   | 0.00
   3  | cherry   | 0.00

  select a.empid,b.prodname,0.00 as rate
  from a as a cross join b as b