def deleteStudent(self, student_id):
''' Delete student entity given student id'''
try:
response = ""
# Create a key for given student id
s_key = ndb.Key(Student, student_id)
# Fetching student entity
#student = Student.get_by_id(student_id)
#print ("Student Record to be deleted = ", student)
if s_key.get():
# 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 = R_DEP_ERR_DELCHILD.format(
"Enrollments", "Student")
else:
# deleting the entity with a given student id
s_key.delete()
response = R_SUCC_DEL.format("Student", str(s_key))
else:
response = R_SERV_ERR.format(
"Unable to retrieve Student entity")
except Exception, e:
response = R_SERV_ERR.format(str(e))
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 insertEnrollment(self, request):
''' Enrollment a student for a course in a given quarter'''
response = ""
# validate all the Referential properties
s_key = ndb.Key(Student, request.student_id)
student = s_key.get()
c_key = ndb.Key(Course, request.course_id)
# retrieve schedule id from schedule
query = self.getSchedule(c_key, request.quarter, request.year)
schedule = query.get()
# Check if schedule exists
if schedule:
schedule_key = schedule.key
# query for existing enrollment. if student id and schedule id exists, duplicate entry
query = self.getEnrollment(s_key, schedule_key)
enrollment = query.get()
print("insertEnrollment method: Enrollment = ", enrollment)
# check if enrollment exists already
if not enrollment:
# validate student ID
if student:
# insert enrollment
enrollment = Enrollment(student=s_key,
schedule=schedule_key)
enrollment.put()
# add course to student study lists
student.study_lists.append(c_key)
student.put()
response = STORED_RESPONSES.items[ADD_ID]
else:
# in valid student ID
response = STORED_RESPONSES.items[INV_STUDENT_ID]
else:
# enrollment already exists
response = STORED_RESPONSES.items[DUPLICATE_ID]
else:
response = STORED_RESPONSES.items[NOT_FOUND_ID]
return response
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 view_students_in_course(self, request):
''' List students enrolled in a course'''
# fetch schedule ids containing the course listed
c_key = ndb.Key(Course, request.course_id)
query = Schedule.query(Schedule.course == c_key)
schedule_keys = []
for key in query.iter(keys_only=True):
schedule_keys.append(key)
# query for enrollments with matching schedule_keys
query = Enrollment.query(Enrollment.schedule.IN(schedule_keys))
print(
"view_students_in_course method: going to convert query to student names message"
)
return self.enrollmentToStudentsMessage(query)
def deleteSchedule(self, schedule):
''' delete a schedule given course ID quarter and year'''
try:
# Get Course id
c_key = schedule.course
# Get schedule id from given year, quarter and course
'''query = Schedule.query(Schedule.course == c_key, Schedule.quarter == int(schedule.quarter),
Schedule.year == int(schedule.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()
response = R_SUCC_DEL.format(
"Schedule",
str(schedule.year) + "-" + str(schedule.quarter) + "-" +
str(schedule.course_id))
else:
response = R_SERV_ERR.format(
"Unable to read data from Schedule Entity")
except Exception, e:
response = R_SERV_ERR.format(str(e))
def insertEnrollment(self, request):
''' Enrollment a student for a course in a given quarter'''
response = ""
# read all input variables
student_id = request.get('student_id')
course_id = request.get('course_id')
year = request.get('year')
quarter = request.get('quarter')
# check for required fields
if (student_id and course_id and year and quarter):
# validate inputs
if (is_int(student_id) and is_int(course_id)):
if (is_int(year) and is_int(quarter)):
student_id = int(student_id)
course_id = int(course_id)
year = int(year)
quarter = int(quarter)
# validate all the Referential properties
s_key = ndb.Key(Student, student_id)
student = s_key.get()
c_key = ndb.Key(Course, course_id)
# retrieve schedule id from schedule
query = self.getSchedule(c_key, quarter, year)
schedule = query.get()
# Check if schedule exists
if schedule:
#schedule_key = schedule.key
# query for existing enrollment. if student id and schedule id exists, duplicate entry
query = self.getEnrollment(s_key, schedule.key)
enrollment = query.get()
# check if enrollment exists already
if not enrollment:
# validate student ID
if student:
# insert enrollment
enrollment = Enrollment(student=s_key,
schedule=schedule.key)
e_key = enrollment.put()
# add course to student study lists
student.study_lists.append(c_key)
student.put()
response = R_SUCC_INSERT.format(
"Enrollments", str(e_key))
else:
# in valid student ID
response = R_DEP_ERR_INVST
else:
# enrollment already exists
response = R_DUP_ID_ERR.format("Enrollment")
else:
response = R_INV_ID_ERR.format("Enrollments")
else:
response = R_PROP_VAL_ERR.format(
"Year and Quarter",
"integers of values (previous year, current year and next year) and range(1-4)"
)
else:
response = R_ID_VAL_ERR.format("Student and Course")
else:
response = R_REQ_FIELD_ERR.format(
"Student ID, Course ID, Year and Quarter")
return response
def getEnrollment(self, student_key, schedule_key):
return Enrollment.query(Enrollment.student == student_key,
Enrollment.schedule == schedule_key)