def __init__(self, provider):
error_message = "The provider cannot be None. If you meant to use the CollectionProvider pass in a tuple or list"
Guard.against_none(provider, error_message)
if isinstance(provider, (list, tuple)):
self.provider = CollectionProvider(provider)
else:
self.provider = provider
self.expressions = []
self.order_expressions = []
self.group_expression = None
self.parser = ExpressionParser()
class Query(object):
def __init__(self, provider):
error_message = "The provider cannot be None. If you meant to use the CollectionProvider pass in a tuple or list"
Guard.against_none(provider, error_message)
if isinstance(provider, (list, tuple)):
self.provider = CollectionProvider(provider)
else:
self.provider = provider
self.expressions = []
self.order_expressions = []
self.group_expression = None
self.parser = ExpressionParser()
def where(self, clause):
self.expressions.append(self.parser.parse(clause.strip()))
return self
def group_by(self, *args):
for arg in args:
self.group_expression = self.parser.parse(arg.strip())
return self
def order_by(self, *args):
for arg in args:
self.order_expressions.append(self.parser.parse(arg.strip()))
return self
def select(self, *cols):
empty_message = "Selecting with no fields is not valid. " \
+ "When using From(provider).select method, " \
+ "please provide a list of expressions or strings as fields."
Guard.against_empty(cols, empty_message)
for col in cols:
Guard.against_empty(col, empty_message)
Guard.accepts_only(cols, [str, Expression], "Selecting with invalid type. " \
+ "When using From(provider).select method, " \
+ "please provide a list of expressions or strings as fields.")
return self.provider.parse(self, action=Actions.Select, cols=cols)
def select_many(self):
return self.provider.parse(self, action=Actions.SelectMany)
def count(self):
return self.provider.parse(self, action=Actions.Count)
def max(self, column="item"):
return self.provider.parse(self, action=Actions.Max, column=column)
def min(self, column="item"):
return self.provider.parse(self, action=Actions.Min, column=column)
def sum(self, column="item"):
return self.provider.parse(self, action=Actions.Sum, column=column)
def avg(self, column="item"):
return self.provider.parse(self, action=Actions.Avg, column=column)
