def generate_filter_expression(filter_key: str, filter_cond: str,
filter_value: str) -> dict:
filter_attr = Attr(filter_key)
if filter_cond == "eq":
return {"FilterExpression": filter_attr.eq(filter_value)}
elif filter_cond == "ne":
return {"FilterExpression": filter_attr.eq(filter_value)}
elif filter_cond == "gt":
return {"FilterExpression": filter_attr.gt(filter_value)}
elif filter_cond == "ge":
return {"FilterExpression": filter_attr.gte(filter_value)}
elif filter_cond == "lt":
return {"FilterExpression": filter_attr.lt(filter_value)}
elif filter_cond == "le":
return {"FilterExpression": filter_attr.lte(filter_value)}
elif filter_cond == "begins_with":
return {"FilterExpression": filter_attr.begins_with(filter_value)}
elif filter_cond == "between":
return {"FilterExpression": filter_attr.between(*[filter_value])}
elif filter_cond == "contains":
return {"FilterExpression": filter_attr.contains(filter_value)}
else:
raise AttributeError("filter condition missing")
def test_build_expression_gte(self):
a = Attr('myattr')
self.assert_condition_expression_build(a.gte('foo'), '#n0 >= :v0',
{'#n0': 'myattr'},
{':v0': 'foo'})
def test_build_expression_gte(self):
a = Attr('myattr')
self.assert_condition_expression_build(
a.gte('foo'), '#n0 >= :v0', {'#n0': 'myattr'}, {':v0': 'foo'})
def test_build_expression_gte(self):
a = Attr("myattr")
self.assert_condition_expression_build(a.gte("foo"), "#n0 >= :v0", {"#n0": "myattr"}, {":v0": "foo"})
def doquery(self, queryspec):
db = boto3.resource('dynamodb')
table = db.Table(queryspec.DataType)
data = None
if len(queryspec.Filters) == 0:
response = table.scan()
data = response['Items']
while 'LastEvaluatedKey' in response:
response = table.scan(
ExclusiveStartKey=response['LastEvaluatedKey'])
data.extend(response['Items'])
else:
for prop in queryspec.Filters:
if data is None and queryspec.Filters[prop][2]: # queryable
key = Key(prop)
if queryspec.Filters[prop][0] == '=':
expr = key.eq(queryspec.Filters[prop][1])
elif queryspec.Filters[prop][0] == '<':
expr = key.lt(queryspec.Filters[prop][1])
elif queryspec.Filters[prop][0] == '>':
expr = key.gt(queryspec.Filters[prop][1])
elif queryspec.Filters[prop][0] == '<=':
expr = key.lte(queryspec.Filters[prop][1])
elif queryspec.Filters[prop][0] == '>=':
expr = key.gte(queryspec.Filters[prop][1])
elif queryspec.Filters[prop][0] == 'btw':
expr = key.between(queryspec.Filters[prop][1][0],
queryspec.Filters[prop][1][0])
response = table.query(KeyConditionExpression=expr)
data = response['Items']
else: # queryable = False
if data is None:
attr = Attr(prop)
if queryspec.Filters[prop][0] == '=':
expr = attr.eq(queryspec.Filters[prop][1])
elif queryspec.Filters[prop][0] == '<':
expr = attr.lt(queryspec.Filters[prop][1])
elif queryspec.Filters[prop][0] == '>':
expr = attr.gt(queryspec.Filters[prop][1])
elif queryspec.Filters[prop][0] == '<=':
expr = attr.lte(queryspec.Filters[prop][1])
elif queryspec.Filters[prop][0] == '>=':
expr = attr.gte(queryspec.Filters[prop][1])
elif queryspec.Filters[prop][0] == 'btw':
expr = attr.between(queryspec.Filters[prop][1][0],
queryspec.Filters[prop][1][0])
response = table.scan(FilterExpression=expr)
data = response['Items']
while 'LastEvaluatedKey' in response:
response = table.scan(
ExclusiveStartKey=response['LastEvaluatedKey'])
data.extend(response['Items'])
else:
pass # TODO: Secondary value
if data is None or len(data) == 0 or len(queryspec.Sorts) == 0:
return data
sortproperty = next(iter(queryspec.Sorts))
sorteddata = sorted(data, key=lambda item: item[sortproperty])
return sorteddata