我们从Python开源项目中，提取了以下12个代码示例，用于说明如何使用django.db.models.fields.CharField()。
def set_chars(instance, field, max_length=255): """ CharField """ possibles = [] possibles.extend(get_field_choices(field)) if possibles: setattr(instance, field.name, random.choice(possibles)) return max_length = min(max_length, field.max_length or 16 * 1024) for validator in field.validators: if isinstance(validator, MaxLengthValidator): max_length = min(max_length, validator.limit_value) value = generate_lorem_ipsum(1, min_len=1, max_len=max(5, max_length // 8), html=False) value = Truncator(value).chars(max_length, html=False) setattr(instance, field.name, value)
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 output_field(self): ''' The type of field used to Cast/Coalesce to. Mainly because a max_length argument is required for CharField until this PR is merged: https://github.com/django/django/pull/8758 ''' Field = self.original_field.__class__ if isinstance(self.original_field, fields.CharField): return Field(max_length=self.original_field.max_length) return Field()
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_internal_type(self): return 'CharField'
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): """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 export_selected_data(self,request,queryset): ops = self.model._meta workbook = xlwt.Workbook(encoding='utf-8') dd = datetime.date.today().strftime('%Y%m%d') file_name = force_text(ops.verbose_name+dd) sheet = workbook.add_sheet(force_text(ops.verbose_name)) obj_fields = getattr(self,'export_fields',None) or self.list_display or self.fields head_col_index = 0 for field in obj_fields: col_name = field try: f = ops.get_field(field) col_name = f.verbose_name except Exception,e: f = getattr(self.model,field) if hasattr(f,'short_description'): col_name = f.short_description sheet.write(0,head_col_index,force_text(col_name)) head_col_index+=1 row_index = 1 for obj in queryset: col_index = 0 for field in obj_fields: f = field try: f = ops.get_field(field) except Exception,e: pass v = getattr(obj,field,'') if hasattr(v,'__call__') or callable(v): v = v() elif type(f) == fields.DateField: v = v.strftime('%Y-%m-%d') elif type(f) == fields.DateTimeField: v = v.strftime('%Y-%m-%d %H:%M') elif type(f) == fields.CharField and f.choices: fc = 'get_'+field+'_display' v = getattr(obj,fc)() elif type(f) == related.ForeignKey: v = str(v) sheet.write(row_index,col_index,v) col_index += 1 row_index += 1 response = HttpResponse(content_type='application/vnd.ms-excel') agent = request.META.get('HTTP_USER_AGENT') nn = smart_str(file_name) if agent and re.search('MSIE',agent): nn = urlquote(file_name) response['Content-Disposition'] = 'attachment; filename=%s.xls'%nn workbook.save(response) return response #self.message_user(request,'SUCCESS')
