lambdaquery/examples.py at master · xnmp-archive/lambdaquery · GitHub

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from example_tables import *

# %% ^━━━━━━━━━━━━━━━━━━  ━━━━━━━━━━━━━━━━━━━━━━━━━━━^

ex1 = School.query()
ex2 = School.query(lambda x: x.campus == 'south')
ex3 = School.query().sort(lambda x: x.campus)
ex4 = School.query().fmap(lambda x: x.name % x.campus)
ex4 = School.query()['name','campus']

@do(Query)
def ex4():
    sc0 = yield School.query()
    returnM (sc0.name, sc0.campus)

@do(Query)
def ex5():
    sc0 = yield School.query()
    returnM (
             sc0.name,
             sc0.departments().count()
            )

@do(Query)
def ex6():
    dept0 = yield Department.query()
    returnM (
             dept0.name,
             dept0.school.name,
             dept0.school.campus
            )

@injective()
def num_dept(self):
    return self.departments().count()

@do(Query)
def ex7():
    sc0 = yield School.query(lambda x: x.num_dept > 3)
    returnM (
             sc0.code,
             sc0.num_dept
            )

ex7 = School.query(lambda x: x.num_dept > 3).fmap(lambda x: x.code % x.num_dept)
ex7 = School.query(lambda x: x.num_dept > 3)[['code','num_dept']]

@do(Query)
def ex8():
    cs0 = yield Course.query()
    returnM (
             cs0.no.like_('100%'),
             cs0.credits.avg_()
            )

@do(Query)
def ex9():
    sc0 = yield School.query()
    dept0 = yield sc0.departments()
    cs0 = yield dept0.courses()
    returnM (
             sc0.name,
             dept0.name,
             cs0.title
            )

# %% ^━━━━━━━━━━━━━━━━━━  ━━━━━━━━━━━━━━━━━━━━━━━━━━━^

# AGGREGATION

ex10 = Department.query().count()

ex11 = School.query().avg('num_dept')

@do(Query)
def ex12():
    dept0 = yield Department.query()
    cs = dept0.courses()
    returnM (
             dept0.name,
             cs.count(),
             cs.max('credits'),
             cs.sum('credits'),
             dept0.courses(lambda x: x.title.like_('Introduction%')).count()
            )

# %% ^━━━━━━━━━━━━━━━━━━  ━━━━━━━━━━━━━━━━━━━━━━━━━━━^


@do(Query)
def ex13():
    sc0 = yield School.query()
    returnM (
             sc0.name,
             sc0.programs()['degree'].count(),
            )


@do(Query)
def ex14():
    dept0 = yield Department.query()
    returnM (
             dept0.name,
             dept0.school.campus
            )


@do(Query)
def ex15():
    dept0 = yield Department.query()
    returnM (
             dept0.name,
             dept0.courses(lambda x: x.credits > 2).lj().count().coalesce_(0)
            )

@do(Query)
def ex15():
    sc0 = yield School.query()
    returnM (
             sc0.name,
             sc0.departments(lambda x: x.courses(lambda y: y.credits > 2)
                             .exists())
                .lj().count().coalesce_(0)
            )

@do(Query)
def ex16():
    sc0 = yield School.query()
    returnM (
             sc0.campus,
             sc0.departments().lj().count()
            )

@Lifted
def coursestart(course, start):
    return (course.no > start) & (course.no < start + 99)


@do(Query)
def ex17():
    dept0 = yield Department.query()
    returnM (
             dept0.name,
             *[dept0.courses(lambda x: x.coursestart(i*100)).count() for i in range(1,5)]
            )

@injective()
def high_credit_count(self):
    return self.courses(lambda x: x.credits > 3).count()

@do(Query)
def ex18():
    sc0 = yield School.query(lambda x: x.programs().exists())
    returnM (
             sc0.name,
             sc0.departments()['high_credit_count'].avg()
            )


@do(Query)
def ex19():
    sc0 = yield School.query(lambda x: x.programs(lambda y: y.title == x.name)
                                        .count() >= 5)
    returnM (
             sc0.name,
             sc0.departments()
                .fmap(lambda x: x.courses(lambda y: y.credits > 3).count())
                .lj().avg()
            )

print(ex19().sql(debug=True))