问找不到ORA-00942父密钥

EN

create table Researcher
  (Pid number(7),
   lname varchar2(12),
   fname char(10),
   constraint pkResearcher PRIMARY KEY(Pid));

create table Project
  (ProjId char(10),
   MedicName varchar2(10),
   Purpose varchar2(12),
   Start_date date,
   End_date date,
   PI_Id number (7),
   constraint pkProject PRIMARY KEY(ProjId),
   constraint fkProject FOREIGN KEY (PI_Id) references Researcher);

insert into Project
values ('PR001','Medic1','heart','1-SEP-2017','31-JUL-2019','10001');

insert into Project
values ('PR005','Medic5','blood','10-JUL-18','31-JAN-20','10102');