Python django.db.models.fields.CharField() Examples

def _build_search_filter(cls, field_name):
    if field_name == "bnf_code":
        return _build_search_filter_bnf_code_prefox()

    field = cls._meta.get_field(field_name)
    builder = {
        ForeignKey: _build_search_filter_fk,
        ManyToOneRel: _build_search_filter_rev_fk,
        OneToOneRel: _build_search_filter_rev_fk,
        fields.CharField: _build_search_filter_char,
        fields.DateField: _build_search_filter_date,
        fields.BooleanField: _build_search_filter_boolean,
        fields.DecimalField: _build_search_filter_decimal,
    }[type(field)]
    search_filter = builder(field)
    search_filter["id"] = field_name
    return search_filter 

def build_schema_from_model(model):
    field_mappings = {
        model_fields.BigIntegerField: "INTEGER",
        model_fields.CharField: "STRING",
        model_fields.DateField: "DATE",
        model_fields.FloatField: "FLOAT",
        model_fields.DecimalField: "NUMERIC",
        model_fields.IntegerField: "INTEGER",
        model_fields.BooleanField: "BOOLEAN",
        model_fields.NullBooleanField: "BOOLEAN",
        model_fields.TextField: "STRING",
        related_fields.ForeignKey: "INTEGER",
        related_fields.OneToOneField: "INTEGER",
    }

    fields = [
        (f.name, field_mappings[type(f)])
        for f in model._meta.fields
        if not f.auto_created
    ]

    return build_schema(*fields) 

def test_field_rename_inside_atomic_block(self):
        """
        NotImplementedError is raised when a model field rename is attempted
        inside an atomic block.
        """
        new_field = CharField(max_length=255, unique=True)
        new_field.set_attributes_from_name('renamed')
        msg = (
            "Renaming the 'backends_author'.'name' column while in a "
            "transaction is not supported on SQLite < 3.26 because it would "
            "break referential integrity. Try adding `atomic = False` to the "
            "Migration class."
        )
        with self.assertRaisesMessage(NotSupportedError, msg):
            with connection.schema_editor(atomic=True) as editor:
                editor.alter_field(Author, Author._meta.get_field('name'), new_field) 

def test_field_rename_inside_atomic_block(self):
        """
        NotImplementedError is raised when a model field rename is attempted
        inside an atomic block.
        """
        new_field = CharField(max_length=255, unique=True)
        new_field.set_attributes_from_name('renamed')
        msg = (
            "Renaming the 'backends_author'.'name' column while in a "
            "transaction is not supported on SQLite because it would break "
            "referential integrity. Try adding `atomic = False` to the "
            "Migration class."
        )
        with self.assertRaisesMessage(NotSupportedError, msg):
            with connection.schema_editor(atomic=True) as editor:
                editor.alter_field(Author, Author._meta.get_field('name'), new_field) 

def get_django_field_map(self):
        from django.db.models import fields as djf
        return [
            (djf.AutoField, PrimaryKeyField),
            (djf.BigIntegerField, BigIntegerField),
            # (djf.BinaryField, BlobField),
            (djf.BooleanField, BooleanField),
            (djf.CharField, CharField),
            (djf.DateTimeField, DateTimeField),  # Extends DateField.
            (djf.DateField, DateField),
            (djf.DecimalField, DecimalField),
            (djf.FilePathField, CharField),
            (djf.FloatField, FloatField),
            (djf.IntegerField, IntegerField),
            (djf.NullBooleanField, partial(BooleanField, null=True)),
            (djf.TextField, TextField),
            (djf.TimeField, TimeField),
            (djf.related.ForeignKey, ForeignKeyField),
        ] 

def build_column_filter(column_name, column_obj, column_spec, search_value):
    search_filter = None

    # if type(column_obj.model_field) == fields.CharField:
    #     # do something special with this field

    choices = column_spec['choices']
    if column_obj.has_choices_available:

        if choices:
            # Since we're using choices (we provided a select box)
            # just use the selected key
            values = [search_value, ]
        else:
            values = column_obj.search_in_choices(search_value)

        search_filter = Q(**{column_obj.name + '__in': values})

    elif isinstance(column_obj.model_field, (models.DateTimeField, models.DateField)):
        try:
            parsed_date = parse_date(search_value)
            date_range = [parsed_date.isoformat(), parsed_date.isoformat()]
            query_param_name = column_obj.get_field_search_path()
            if isinstance(column_obj.model_field, models.DateTimeField):
                search_filter = Q(**{query_param_name + '__date__range': date_range})
            else:
                search_filter = Q(**{query_param_name + '__range': date_range})
        except ValueError:
            pass
    else:
        query_param_name = column_obj.get_field_search_path()
        #search_filters |= Q(**{query_param_name + '__istartswith': search_value})
        search_filter = Q(**{query_param_name + '__icontains': search_value})

    return search_filter 

def get_field_nullability(self, field: Union[Field, ForeignObjectRel], method: Optional[str]) -> bool:
        nullable = field.null
        if not nullable and isinstance(field, CharField) and field.blank:
            return True
        if method == '__init__':
            if ((isinstance(field, Field) and field.primary_key)
                    or isinstance(field, ForeignKey)):
                return True
        if method == 'create':
            if isinstance(field, AutoField):
                return True
        if isinstance(field, Field) and field.has_default():
            return True
        return nullable 

def _build_lookup_key(cls, field_name, operator):
    field = cls._meta.get_field(field_name)
    builder = {
        ForeignKey: _build_lookup_fk,
        ManyToOneRel: _build_lookup_rev_fk,
        OneToOneRel: _build_lookup_rev_fk,
        fields.CharField: _build_lookup_char,
        fields.DateField: _build_lookup_date,
        fields.BooleanField: _build_lookup_boolean,
        fields.DecimalField: _build_lookup_decimal,
    }[type(field)]
    return builder(cls, field_name, operator) 

def test_get_data_field(self):
        field_info = self._details(Person, Person._meta.get_field('data_abstract'))
        self.assertEqual(field_info[1:], (BasePerson, True, False))
        self.assertIsInstance(field_info[0], CharField) 

def test_get_data_field(self):
        field_info = self._details(Person, Person._meta.get_field('data_abstract'))
        self.assertEqual(field_info[1:], (BasePerson, True, False))
        self.assertIsInstance(field_info[0], CharField) 

def __init__(self, *args, **kwargs):
        # Local import so the languages aren't loaded unless they are needed.
        from .languages import LANGUAGES

        kwargs.setdefault('max_length', 3)
        kwargs.setdefault('choices', LANGUAGES)
        super(CharField, self).__init__(*args, **kwargs) 

def get_search_results(self, request, queryset, search_term):
        if '-' in search_term and search_term[-1].isdigit():
            return queryset \
                .annotate(_series_number=Concat(F('series'), Value('-'), F('number'),
                                                output_field=fields.CharField())) \
                .filter(_series_number=search_term), True

        return super(BillingDocumentAdmin, self).get_search_results(request, queryset, search_term) 

def lookups(self, request, model_admin):
        queryset = model_admin.get_queryset(request)

        proformas_queryset = Proforma.objects \
            .filter(proforma_transactions__in=queryset.distinct()) \
            .annotate(_series_number=Concat(F('series'), Value('-'), F('number'),
                                            output_field=fields.CharField())) \
            .values_list('id', '_series_number') \
            .distinct()

        return list(proformas_queryset) 

def lookups(self, request, model_admin):
        queryset = model_admin.get_queryset(request)

        invoices_queryset = Invoice.objects \
            .filter(invoice_transactions__in=queryset.distinct()) \
            .annotate(_series_number=Concat(F('series'), Value('-'), F('number'),
                                            output_field=fields.CharField())) \
            .values_list('id', '_series_number') \
            .distinct()

        return list(invoices_queryset) 

def lookups(self, request, model_admin):
        queryset = model_admin.get_queryset(request).distinct() \
            .annotate(
                _name_provider=Concat(
                    F('plan__name'), Value(' ('), F('plan__provider__name'), Value(')'),
                    output_field=fields.CharField()
                ),
        ) \
            .values_list('id', '_name_provider') \
            .distinct()

        return list(queryset) 

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) 

def _raw_sql(self, values: List[Tuple[Union[str, int], Union[str, int]]]) -> str:
        """Prepare SQL statement consisting of a sequence of WHEN .. THEN statements."""
        if isinstance(self.model._meta.pk, CharField):
            when_clauses = " ".join(
                [self._when("'{}'".format(x), y) for (x, y) in values]
            )
        else:
            when_clauses = " ".join([self._when(x, y) for (x, y) in values])
        table_name = self.model._meta.db_table
        primary_key = self.model._meta.pk.column
        return 'SELECT CASE {}."{}" {} ELSE 0 END'.format(
            table_name, primary_key, when_clauses
        ) 

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) 

def get_comparison_class(self):
        # Hide fields with hidden widget
        widget_override = self.widget_overrides().get(self.field_name, None)
        if widget_override and widget_override.is_hidden:
            return

        try:
            field = self.db_field

            if field.choices:
                return compare.ChoiceFieldComparison

            if field.is_relation:
                if isinstance(field, TaggableManager):
                    return compare.TagsFieldComparison
                elif field.many_to_many:
                    return compare.M2MFieldComparison

                return compare.ForeignObjectComparison

            if isinstance(field, RichTextField):
                return compare.RichTextFieldComparison

            if isinstance(field, (CharField, TextField)):
                return compare.TextFieldComparison

        except FieldDoesNotExist:
            pass

        return compare.FieldComparison