本文整理匯總了Python中django.db.models.expressions.Value類的典型用法代碼示例。如果您正苦於以下問題：Python Value類的具體用法？Python Value怎麽用？Python Value使用的例子？那麽, 這裏精選的類代碼示例或許可以為您提供幫助。
在下文中一共展示了Value類的5個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的Python代碼示例。
示例1: __init__
def __init__(self, expression, distinct=False, **extra):
if expression == "*":
expression = Value(expression)
expression._output_field = IntegerField()
super(Count, self).__init__(
expression, distinct="DISTINCT " if distinct else "", output_field=IntegerField(), **extra
)示例2: process_rhs
def process_rhs(self, compiler, connection):
value = self.rhs
if self.bilateral_transforms:
if self.rhs_is_direct_value():
# Do not call get_db_prep_lookup here as the value will be
# transformed before being used for lookup
value = Value(value, output_field=self.lhs.output_field)
value = self.apply_bilateral_transforms(value)
value = value.resolve_expression(compiler.query)
if hasattr(value, 'as_sql'):
return compiler.compile(value)
else:
return self.get_db_prep_lookup(value, connection)示例3: batch_process_rhs
def batch_process_rhs(self, compiler, connection, rhs=None):
if rhs is None:
rhs = self.rhs
if self.bilateral_transforms:
sqls, sqls_params = [], []
for p in rhs:
value = Value(p, output_field=self.lhs.output_field)
value = self.apply_bilateral_transforms(value)
value = value.resolve_expression(compiler.query)
sql, sql_params = compiler.compile(value)
sqls.append(sql)
sqls_params.extend(sql_params)
else:
_, params = self.get_db_prep_lookup(rhs, connection)
sqls, sqls_params = ['%s'] * len(params), params
return sqls, sqls_params示例4: process_rhs
def process_rhs(self, compiler, connection):
value = self.rhs
if self.bilateral_transforms:
if self.rhs_is_direct_value():
# Do not call get_db_prep_lookup here as the value will be
# transformed before being used for lookup
value = Value(value, output_field=self.lhs.output_field)
value = self.apply_bilateral_transforms(value)
value = value.resolve_expression(compiler.query)
# Due to historical reasons there are a couple of different
# ways to produce sql here. get_compiler is likely a Query
# instance and as_sql just something with as_sql. Finally the value
# can of course be just plain Python value.
if hasattr(value, 'get_compiler'):
value = value.get_compiler(connection=connection)
if hasattr(value, 'as_sql'):
sql, params = compiler.compile(value)
return '(' + sql + ')', params
else:
return self.get_db_prep_lookup(value, connection)