Python models.Func方法代码示例

# 需要导入模块: from django.db import models [as 别名]
# 或者: from django.db.models import Func [as 别名]
def clean_domain_name(field_name):
    """
    Returns a Django query expression that replaces all underscores with a
    hyphen, removes leading and trailing hyphens, and converts the field to
    lower case.
    """
    remove_underscores = Func(
        F(field_name),
        Value('_'),
        Value('-'),
        function='replace'
    )
    trim_hyphens = Func(
        remove_underscores,
        Value('-'),
        function='btrim',
    )
    remove_trailing_hyphens = Func(
        trim_hyphens,
        Value(r'[-]+\.'),
        Value('.'),
        Value('g'),
        function='regexp_replace'
    )
    return Lower(remove_trailing_hyphens) 

# 需要导入模块: from django.db import models [as 别名]
# 或者: from django.db.models import Func [as 别名]
def change_metakey_case(self, metakey, operation, modifier=None):
        available_operations = {'lowercase': lowercase,
                                'uppercase': uppercase,
                                'capitalize': capitalize}

        edit = available_operations.get(operation, None)

        if edit:

            if modifier:
                new_metakey = metakey.replace(modifier, edit(modifier))
            else:
                new_metakey = edit(metakey)

            # Copy old metadata into an hstore container with new key value
            TEMP_HSTORE = Func(Value(new_metakey), GET_VALUE('metadata') + Value(metakey), function='hstore')

            # Delete old key entry from original hstore
            META_HSTORE = Func(F('metadata'), Value(metakey), function='delete')

            # Combine the two hstores using internal 'hs_concat' function
            CONCAT_HSTORE = Func(TEMP_HSTORE, META_HSTORE, function='hs_concat')

            self.filter(metadata__has_key=metakey).update(metadata=CONCAT_HSTORE) 

# 需要导入模块: from django.db import models [as 别名]
# 或者: from django.db.models import Func [as 别名]
def set_metadata(self, metakey, metavalue):

        if check_lexical_convention(metakey) and \
        (metavalue.isdigit() or metavalue in ('true', 'false') or \
        (metavalue.startswith('\"') and metavalue.endswith('\"'))):

            # Copy old metadata into an hstore container with new key value
            TEMP_HSTORE = Func(Value(metakey), Value(metavalue), function='hstore')

            # Delete old key entry from original hstore
            META_HSTORE = Func(F('metadata'), Value(metakey), function='delete')

            # Combine the two hstores using internal 'hs_concat' function
            CONCAT_HSTORE = Func(TEMP_HSTORE, META_HSTORE, function='hs_concat')

            self.update(metadata=CONCAT_HSTORE) 

# 需要导入模块: from django.db import models [as 别名]
# 或者: from django.db.models import Func [as 别名]
def infer_practice_boundaries():
    practices = Practice.objects.filter(location__isnull=False, setting=4).exclude(
        status_code__in=(
            Practice.STATUS_RETIRED,
            Practice.STATUS_DORMANT,
            Practice.STATUS_CLOSED,
        )
    )
    partition = practices.aggregate(
        voronoi=Func(Collect("location"), function="ST_VoronoiPolygons")
    )["voronoi"]
    national_boundary = get_national_boundary()
    practice_regions = get_practice_code_to_region_map(partition, national_boundary)
    with transaction.atomic():
        for practice in practices:
            practice.boundary = practice_regions[practice.code]
            practice.save(update_fields=["boundary"]) 

# 需要导入模块: from django.db import models [as 别名]
# 或者: from django.db.models import Func [as 别名]
def as_oracle(self, compiler, connection):
        # we can't mix TextField (NCLOB) and CharField (NVARCHAR), so convert
        # all fields to NCLOB when we expect NCLOB
        if self.output_field.get_internal_type() == 'TextField':
            class ToNCLOB(Func):
                function = 'TO_NCLOB'

            expressions = [
                ToNCLOB(expression) for expression in self.get_source_expressions()]
            clone = self.copy()
            clone.set_source_expressions(expressions)
            return super(Coalesce, clone).as_sql(compiler, connection)
        return self.as_sql(compiler, connection) 

# 需要导入模块: from django.db import models [as 别名]
# 或者: from django.db.models import Func [as 别名]
def populate_date_range(apps, schema_editor):
    Activity = apps.get_model('activities', 'Activity')

    # initializes the date_range field with a range of (date, date + 30 minutes)
    Activity.objects.all().update(
        date_range=Func(F('date'), F('date') + timedelta(minutes=30), function='tstzrange')
    ) 

# 需要导入模块: from django.db import models [as 别名]
# 或者: from django.db.models import Func [as 别名]
def __init__(self, lhs, rhs):
        super().__init__(Func(Func(lhs, function='F_UNACCENT'), function='UPPER'), Func(Func(rhs, function='F_UNACCENT'), function='UPPER')) 

# 需要导入模块: from django.db import models [as 别名]
# 或者: from django.db.models import Func [as 别名]
def get_prep_value(self, value):
        # convert the Molecule instance to the value used by the
        # db driver
        if isinstance(value, str):
            value = self.text_to_mol(value)
        if isinstance(value, Chem.Mol):
            value = memoryview(value.ToBinary())
        if value is None:
            return None
        return Func(value, function='mol_from_pkl') 

# 需要导入模块: from django.db import models [as 别名]
# 或者: from django.db.models import Func [as 别名]
def as_oracle(self, compiler, connection):
        # Oracle prohibits mixing TextField (NCLOB) and CharField (NVARCHAR2),
        # so convert all fields to NCLOB when that type is expected.
        if self.output_field.get_internal_type() == 'TextField':
            class ToNCLOB(Func):
                function = 'TO_NCLOB'

            expressions = [
                ToNCLOB(expression) for expression in self.get_source_expressions()
            ]
            clone = self.copy()
            clone.set_source_expressions(expressions)
            return super(Coalesce, clone).as_sql(compiler, connection)
        return self.as_sql(compiler, connection) 

# 需要导入模块: from django.db import models [as 别名]
# 或者: from django.db.models import Func [as 别名]
def current_event_types(self):
        qs = (ProbeSource.objects.annotate(event_type=Func(F("event_types"), function="unnest"))
                                 .values("event_type").distinct().order_by())
        return sorted(((rd["event_type"], event_types[rd["event_type"]].get_event_type_display())
                       for rd in qs),
                      key=lambda t: t[1]) 

# 需要导入模块: from django.db import models [as 别名]
# 或者: from django.db.models import Func [as 别名]
def test_Func_expresion(self):

        # initialize
        ini_values = 'aA', 'BB', '', 'cc', '12'
        people = Person.objects.order_by('pk').all()
        for value, person in zip(ini_values, people):
            person.name = value
            person.text = value*2
            person.save()

        # set
        people = Person.objects.order_by('pk').all()
        for person in people:
            person.name = Func(F('name'), function='UPPER')
            person.text = Func(F('text'), function='LOWER')

        # update
        Person.objects.bulk_update(people)

        # check
        people = Person.objects.order_by('pk').all()

        expected_values = 'AA', 'BB', '', 'CC', '12'
        for expected_value, person in zip(expected_values, people):
            saved_value = person.name
            self.assertEqual(saved_value, expected_value)

        expected_values = 'aaaa', 'bbbb', '', 'cccc', '1212'
        for expected_value, person in zip(expected_values, people):
            saved_value = person.text
            self.assertEqual(saved_value, expected_value) 

# 需要导入模块: from django.db import models [as 别名]
# 或者: from django.db.models import Func [as 别名]
def test_already_evaluated_queryset(self):
        """
        Queries:
            - update objects

        (objects are already retrieved, because of the previous loop)
        """
        people = Person.objects.all()
        for person in people:
            person.age += 2
            person.name = Func(F('name'), function='UPPER')
            person.text = 'doc'
            person.height -= Decimal(0.5)
        self.assertNumQueries(1, Person.objects.bulk_update, people) 

# 需要导入模块: from django.db import models [as 别名]
# 或者: from django.db.models import Func [as 别名]
def move_collection_receiver(sender, **kwargs):
    """
    A post_save receiver that is triggered when Collection model objects are changed.
    """
    if kwargs["created"]:
        return
    collection = kwargs["instance"]
    try:
        prev_collection = collection.history.all()[1]
    except IndexError:
        return
    if collection.collection_set != prev_collection.collection_set:
        src_collection_path = get_collection_path(prev_collection)
        dest_collection_path = get_collection_path(collection)
        if not os.path.exists(src_collection_path):
            log.warn("Not moving collection directory since %s does not exist", src_collection_path)
            return
        if os.path.exists(dest_collection_path):
            log.error("Cannot move collection directory %s since %s already exists")
            return
        log.info("Moving %s to %s", src_collection_path, dest_collection_path)
        shutil.move(src_collection_path, dest_collection_path)
        # Update WARC model objects
        Warc.objects.filter(harvest__collection=collection).update(
            path=Func(
                F('path'),
                Value(src_collection_path), Value(dest_collection_path),
                function='replace',
            )
        ) 

# 需要导入模块: from django.db import models [as 别名]
# 或者: from django.db.models import Func [as 别名]
def rename_metakey(self, old_metakey, new_metakey):

        if check_lexical_convention(new_metakey):
            # Copy old metadata into an hstore container with new key value
            TEMP_HSTORE = Func(Value(new_metakey), GET_VALUE('metadata') + Value(old_metakey), function='hstore')

            # Delete old key entry from original hstore
            META_HSTORE = Func(F('metadata'), Value(old_metakey), function='delete')

            # Combine the two hstores using internal 'hs_concat' function
            CONCAT_HSTORE = Func(TEMP_HSTORE, META_HSTORE, function='hs_concat')

            self.filter(metadata__has_key=old_metakey).update(metadata=CONCAT_HSTORE) 

# 需要导入模块: from django.db import models [as 别名]
# 或者: from django.db.models import Func [as 别名]
def _divide(numerator_field, denominator_field):
    """
    SQL division function which handles NULLs and divide-by-zero gracefully
    """
    numerator = Coalesce(numerator_field, Value(0.0))
    denominator = Func(denominator_field, Value(0.0), function="NULLIF")
    return numerator / denominator