finish model relations

port/models.py

@@ -84,6 +84,18 @@ class Port(Model):
     # Foreign keys
     address = ForeignKey(Address)
     company = ForeignKey(Company)
+    employees = ManyToManyField(
+        Person,
+        through='Employee',
+        through_fields=('port', 'person')
+    )
+
+class Employee(Model):
+    position = CharField('Job', max_length=20) 
+
+    # Foreign keys
+    port = ForeignKey(Port)
+    person = ForeignKey(Person)
 
 class Dock(Model):
     num = CharField(max_length=10)
@@ -111,7 +123,7 @@ class Tap(Model):
 
 class Stay(Model):
     arrival = DateTimeField()
-    departure = DateTimeField('date published')
+    departure = DateTimeField()
     coming_from = CharField(max_length=200)
     going_to = CharField(max_length=200)
 
@@ -131,12 +143,12 @@ class Payment(Model):
     pay_type = ForeignKey(PaymentType)
 
 class Service(Model):
-    service_type = CharField(max_length=50)
+    name = CharField(max_length=50)
 
 class BillLine(Model):
     quantity = DecimalField()
 
-    # Foreign keys
+    # Foreign keyks
     service = ForeignKey(Service)
     bill = ForeignKey(Bill)
 
@@ -145,6 +157,14 @@ class Bill(Model):
     date = DateTimeField()
     total = DecimalField()
 
+    # Foreign keys
+    payments = ManyToManyField(
+        Payment,
+        through='BillPayment',
+        through_fields=('bill', 'payment')
+    )
+
+
 class BillPayment(Model):
     amount = DecimalField()