本文整理汇总了Python中django.db.models.sql.query.Query.get_initial_alias方法的典型用法代码示例。如果您正苦于以下问题:Python Query.get_initial_alias方法的具体用法?Python Query.get_initial_alias怎么用?Python Query.get_initial_alias使用的例子?那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类django.db.models.sql.query.Query
的用法示例。
在下文中一共展示了Query.get_initial_alias方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: _get_field
# 需要导入模块: from django.db.models.sql.query import Query [as 别名]
# 或者: from django.db.models.sql.query.Query import get_initial_alias [as 别名]
def _get_field(model, name):
if django.VERSION[0] >= 1 and django.VERSION[1] >= 8:
# Django 1.8+ - can use something like
# expression.output_field.get_internal_field() == 'Money..'
raise NotImplementedError("Django 1.8+ support is not implemented.")
from django.db.models.fields import FieldDoesNotExist
# Create a fake query object so we can easily work out what field
# type we are dealing with
qs = Query(model)
opts = qs.get_meta()
alias = qs.get_initial_alias()
parts = name.split(LOOKUP_SEP)
# The following is borrowed from the innards of Query.add_filter - it strips out __gt, __exact et al.
num_parts = len(parts)
if num_parts > 1 and parts[-1] in qs.query_terms:
# Traverse the lookup query to distinguish related fields from
# lookup types.
lookup_model = model
for counter, field_name in enumerate(parts):
try:
lookup_field = lookup_model._meta.get_field(field_name)
except FieldDoesNotExist:
# Not a field. Bail out.
parts.pop()
break
# Unless we're at the end of the list of lookups, let's attempt
# to continue traversing relations.
if (counter + 1) < num_parts:
try:
lookup_model = lookup_field.rel.to
except AttributeError:
# Not a related field. Bail out.
parts.pop()
break
if django.VERSION[0] >= 1 and django.VERSION[1] in (6, 7):
# Django 1.6-1.7
field = qs.setup_joins(parts, opts, alias)[0]
else:
# Django 1.4-1.5
field = qs.setup_joins(parts, opts, alias, False)[0]
return field