Database Version

r.md

Employee(EID)
Customer(CID, EID)
Log(CID, Timestamp)

Insert Employee (EID) VALUES (1);
Insert Employee (EID) VALUES (2);
Insert Customer (CID, EID) VALUES (1, 1);
Insert Log (CID, Timestamp) VALUES (1, NOW());
Update Customer Set EID = 2 WHERE CID = 1;