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Merge pull request #2265 from IVIURRAY/bugfix/scan-projection

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ProjectionExpression works with table.scan()
This commit is contained in:
Steve Pulec 2019-07-01 21:21:53 -05:00 • committed by GitHub
commit c8b94b6e9f
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3 changed files with 178 additions and 5 deletions
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16
moto/dynamodb2/models.py
View file

@ -724,7 +724,7 @@ class Table(BaseModel):
if idx_col_set.issubset(set(hash_set.attrs)):
yield hash_set
def scan(self, filters, limit, exclusive_start_key, filter_expression=None, index_name=None):
def scan(self, filters, limit, exclusive_start_key, filter_expression=None, index_name=None, projection_expression=None):
results = []
scanned_count = 0
all_indexes = self.all_indexes()
@ -763,6 +763,14 @@ class Table(BaseModel):
if passes_all_conditions:
results.append(item)
if projection_expression:
expressions = [x.strip() for x in projection_expression.split(',')]
results = copy.deepcopy(results)
for result in results:
for attr in list(result.attrs):
if attr not in expressions:
result.attrs.pop(attr)
results, last_evaluated_key = self._trim_results(results, limit,
exclusive_start_key, index_name)
return results, scanned_count, last_evaluated_key
@ -962,7 +970,7 @@ class DynamoDBBackend(BaseBackend):
return table.query(hash_key, range_comparison, range_values, limit,
exclusive_start_key, scan_index_forward, projection_expression, index_name, filter_expression, **filter_kwargs)
def scan(self, table_name, filters, limit, exclusive_start_key, filter_expression, expr_names, expr_values, index_name):
def scan(self, table_name, filters, limit, exclusive_start_key, filter_expression, expr_names, expr_values, index_name, projection_expression):
table = self.tables.get(table_name)
if not table:
return None, None, None
@ -977,7 +985,9 @@ class DynamoDBBackend(BaseBackend):
else:
filter_expression = Op(None, None) # Will always eval to true
return table.scan(scan_filters, limit, exclusive_start_key, filter_expression, index_name)
projection_expression = ','.join([expr_names.get(attr, attr) for attr in projection_expression.replace(' ', '').split(',')])
return table.scan(scan_filters, limit, exclusive_start_key, filter_expression, index_name, projection_expression)
def update_item(self, table_name, key, update_expression, attribute_updates, expression_attribute_names,
expression_attribute_values, expected=None):

5
moto/dynamodb2/responses.py
View file

@ -558,7 +558,7 @@ class DynamoHandler(BaseResponse):
filter_expression = self.body.get('FilterExpression')
expression_attribute_values = self.body.get('ExpressionAttributeValues', {})
expression_attribute_names = self.body.get('ExpressionAttributeNames', {})
projection_expression = self.body.get('ProjectionExpression', '')
exclusive_start_key = self.body.get('ExclusiveStartKey')
limit = self.body.get("Limit")
index_name = self.body.get('IndexName')
@ -570,7 +570,8 @@ class DynamoHandler(BaseResponse):
filter_expression,
expression_attribute_names,
expression_attribute_values,
index_name)
index_name,
projection_expression)
except InvalidIndexNameError as err:
er = 'com.amazonaws.dynamodb.v20111205#ValidationException'
return self.error(er, str(err))