def deleteStudent(self, request):
''' Delete student entity given student id'''
try:
response = ""
# Create a key for given student id
s_key = ndb.Key(Student, int(request.id))
student = Student.get_by_id(request.id)
print("Key generated for student = ", s_key, student)
# Fetching student entity
#student = Student.get_by_id(s_key)
#student = s_key.get()
#print ("Student Record to be deleted = ", student)
if student:
# check if the student is enrolled in a course or not.
query = Enrollment.query(Enrollment.student == s_key)
if query.get():
# cannot delete student without deleting his enrollments
response = STORED_RESPONSES.items[DEP_ERR_STUDENT_ID]
else:
# deleting the entity with a given student id
s_key.delete()
response = STORED_RESPONSES.items[DELETE_ID]
else:
response = STORED_RESPONSES.items[INV_STUDENT_ID]
return response
except:
raise endpoints.EndpointsErrorMessage(
'Unable to delete student entity. Please try again later.')
def insertStudent(self, request):
''' Insert student entity given student ID'''
try:
response = ""
# Check if student id already exists
student = self.getStudent(request.id)
if not student:
# Check if department is valid
dept = self.getDepartment(request.department_id)
if (not dept):
# Invalid department id
print("Department record not found!", dept)
response = STORED_RESPONSES.items[INV_DEPT_ID]
else:
print("New student record to be added", student)
# insert student entity
response = self.upsertStudent(request, ADD_ID)
else:
#Send Error Message
response = STORED_RESPONSES.items[DUPLICATE_ID]
return response
except:
raise endpoints.EndpointsErrorMessage(
'Unable to add student entity. Please try again later. ')
def deleteDept(self, request):
''' delete department given department ID. delete in the order Schedule, Student and Course first'''
# Enhancement. Deleting entity using other details like department name
try:
# Creating the key for given department id
d_key = ndb.Key(Department, int(request.id))
# Fetching and deleting the entity
dept = Department.get_by_id(request.id)
''' Dependencies'''
# check if department exists in Student kind
st_query = Student.query(Student.department == d_key)
co_query = Course.query(Course.department == d_key)
sch_query = Schedule.query(Schedule.department == d_key)
if sch_query.get():
# entity found in Schedule. Invoke Dependency error
response = STORED_RESPONSES.items[DEP_ERR_DEPT_SCH_ID]
elif st_query.get():
# entity found in Student. Invoke Dependency error
response = STORED_RESPONSES.items[DEP_ERR_DEPT_ST_ID]
elif co_query.get():
# entity found in Course. Invoke Dependency error
response = STORED_RESPONSES.items[DEP_ERR_DEPT_CO_ID]
else:
# no dependencies found. delete department
print("Department to be deleted = ", dept)
d_key.delete()
response = STORED_RESPONSES.items[DELETE_ID]
return response
except:
raise endpoints.EndpointsErrorMessage(
"Unable to delete entity. Please try again later!")
def deleteSchedule(self, request):
''' delete a schedule given course ID quarter and year'''
try:
# Get Course id
c_key = ndb.Key(Course, int(request.course_id))
print("deleteSchedule Method: Going to query object")
# Get schedule id from given year, quarter and course
query = Schedule.query(Schedule.course == c_key,
Schedule.quarter == request.quarter,
Schedule.year == request.year)
print("deleteSchedule method: After query = ", query)
schedule = query.get()
if schedule:
print("deleteSchedule method: schedule -", schedule.key,
" exists for course key = ", c_key)
# delete all enrollments for that schedule
query = Enrollment.query(
Enrollment.schedule ==
schedule.key) #ndb.Key(Schedule, schedule.id))
for enrollment in query.fetch():
print("deleteSchedule Method: Fetching query = ",
enrollment)
# delete course from Student model
student = enrollment.student.get()
print("===========Student list for course========",
student)
if (c_key in student.study_lists):
student.study_lists.remove(c_key)
# update student entity
student.put()
print(
"deleteSchedule method: course not in student list"
)
print(
"deleteSchedule method: Going to delete enrollment with Key = ",
enrollment.key)
# delete enrollment
#enrollment = q.get()
#ndb.Key(Enrollment, enrollment.id).delete()
enrollment.key.delete()
print(
"deleteSchedule method: deleted enrollment successfully"
)
#ndb.Key(Enrollment, q.id).delete()
# delete schedule
schedule.key.delete()
except:
raise endpoints.EndpointsErrorMessage(
'Error while deleting a schedule.')
return STORED_RESPONSES.items[DELETE_ID]
def insertDept(self, request):
try:
''' insert new department given department ID'''
# Checking if the record exists already
department = self.getDepartment(request.id)
if not department:
# New record
print "New Department to be added"
response = self.upsertDepartment(request, ADD_ID)
else:
# Record exists. Cannot insert. Need to update. Send Error message back
response = STORED_RESPONSES.items[DUPLICATE_ID]
return response
except:
raise endpoints.EndpointsErrorMessage(
'Unable to add department record. Please try again later.')
def deleteCourse(self, request):
'''Delete a course given course ID. Delete course from Schedule first.'''
try:
response = ""
# Creating the key for given course id
c_key = ndb.Key(Course, request.id)
# Check if course exists
if c_key.get():
'''Dependency Check'''
# Check if course exists in schedule
query = Schedule.query(Schedule.course == c_key)
if query.get():
# course exists in schedule. Invoke dependency error
response = STORED_RESPONSES.items[DEP_ERR_COURSE_ID]
else:
# Fetching and deleting the entity with given course_id
c_key.delete()
response = STORED_RESPONSES.items[DELETE_ID]
return response
except:
raise endpoints.EndpointsErrorMessage(
'Unable to delete course entity. Please try again later. ')
def insertCourse(self, request):
''' insert a new course given course ID and department ID. course ID is unique across depts.'''
try:
response = ""
course = self.getCourse(request.id)
# check for valid department
department = self.getDepartment(request.department_id)
# Course Not found. Insert new course
if not course:
# Validate department
if department:
# create new course
response = self.upsertCourse(request, ADD_ID)
else:
response = STORED_RESPONSES.items[INV_DEPT_ID]
else:
# Course found. cannot insert but update
response = STORED_RESPONSES.items[DUPLICATE_ID]
return response
except:
raise endpoints.EndpointsErrorMessage(
'Unable to add course record. Please try again later. ')