AWS code-library documentation change
Summary
Added advanced query operations section with consistent reads, GSI usage, pagination, and complex filters
Security assessment
New examples show general query patterns and performance considerations without addressing security controls or vulnerabilities
Diff
diff --git a/code-library/latest/ug/python_3_dynamodb_code_examples.md b/code-library/latest/ug/python_3_dynamodb_code_examples.md index acf01f25c..c8851f869 100644 --- a//code-library/latest/ug/python_3_dynamodb_code_examples.md +++ b//code-library/latest/ug/python_3_dynamodb_code_examples.md @@ -1695 +1695 @@ The following code example shows how to use `Query`. -**SDK for Python (Boto3)** + * Use the begins_with function in a key condition expression. @@ -1696,0 +1697 @@ The following code example shows how to use `Query`. + * Filter items based on a prefix pattern in the sort key. @@ -1698 +1698,0 @@ The following code example shows how to use `Query`. -###### Note @@ -1700 +1699,0 @@ The following code example shows how to use `Query`. -There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples). @@ -1702 +1700,0 @@ There's more on GitHub. Find the complete example and learn how to set up and ru -Query items by using a key condition expression. @@ -1703,0 +1702 @@ Query items by using a key condition expression. +**SDK for Python (Boto3)** @@ -1705,2 +1703,0 @@ Query items by using a key condition expression. - class Movies: - """Encapsulates an Amazon DynamoDB table of movie data. @@ -1708,19 +1705 @@ Query items by using a key condition expression. - Example data structure for a movie record in this table: - { - "year": 1999, - "title": "For Love of the Game", - "info": { - "directors": ["Sam Raimi"], - "release_date": "1999-09-15T00:00:00Z", - "rating": 6.3, - "plot": "A washed up pitcher flashes through his career.", - "rank": 4987, - "running_time_secs": 8220, - "actors": [ - "Kevin Costner", - "Kelly Preston", - "John C. Reilly" - ] - } - } - """ +Query a DynamoDB table using a begins_with condition on the sort key with AWS SDK for Python (Boto3). @@ -1728,8 +1706,0 @@ Query items by using a key condition expression. - def __init__(self, dyn_resource): - """ - :param dyn_resource: A Boto3 DynamoDB resource. - """ - self.dyn_resource = dyn_resource - # The table variable is set during the scenario in the call to - # 'exists' if the table exists. Otherwise, it is set by 'create_table'. - self.table = None @@ -1736,0 +1708,2 @@ Query items by using a key condition expression. + import boto3 + from boto3.dynamodb.conditions import Key @@ -1738,3 +1710,0 @@ Query items by using a key condition expression. - def query_movies(self, year): - """ - Queries for movies that were released in the specified year. @@ -1742,2 +1712,3 @@ Query items by using a key condition expression. - :param year: The year to query. - :return: The list of movies that were released in the specified year. + def query_with_begins_with( + table_name, partition_key_name, partition_key_value, sort_key_name, prefix + ): @@ -1745,12 +1716 @@ Query items by using a key condition expression. - try: - response = self.table.query(KeyConditionExpression=Key("year").eq(year)) - except ClientError as err: - logger.error( - "Couldn't query for movies released in %s. Here's why: %s: %s", - year, - err.response["Error"]["Code"], - err.response["Error"]["Message"], - ) - raise - else: - return response["Items"] + Query a DynamoDB table with a begins_with condition on the sort key. @@ -1757,0 +1718,6 @@ Query items by using a key condition expression. + Args: + table_name (str): The name of the DynamoDB table. + partition_key_name (str): The name of the partition key attribute. + partition_key_value (str): The value of the partition key to query. + sort_key_name (str): The name of the sort key attribute. + prefix (str): The prefix to match at the beginning of the sort key. @@ -1758,0 +1725,6 @@ Query items by using a key condition expression. + Returns: + dict: The response from DynamoDB containing the query results. + """ + # Initialize the DynamoDB resource + dynamodb = boto3.resource("dynamodb") + table = dynamodb.Table(table_name) @@ -1759,0 +1732,5 @@ Query items by using a key condition expression. + # Perform the query with a begins_with condition on the sort key + key_condition = Key(partition_key_name).eq(partition_key_value) & Key( + sort_key_name + ).begins_with(prefix) + response = table.query(KeyConditionExpression=key_condition) @@ -1761 +1738 @@ Query items by using a key condition expression. -Query items and project them to return a subset of data. + return response @@ -1764,43 +1740,0 @@ Query items and project them to return a subset of data. - class UpdateQueryWrapper: - def __init__(self, table): - self.table = table - - - def query_and_project_movies(self, year, title_bounds): - """ - Query for movies that were released in a specified year and that have titles - that start within a range of letters. A projection expression is used - to return a subset of data for each movie. - - :param year: The release year to query. - :param title_bounds: The range of starting letters to query. - :return: The list of movies. - """ - try: - response = self.table.query( - ProjectionExpression="#yr, title, info.genres, info.actors[0]", - ExpressionAttributeNames={"#yr": "year"}, - KeyConditionExpression=( - Key("year").eq(year) - & Key("title").between( - title_bounds["first"], title_bounds["second"] - ) - ), - ) - except ClientError as err: - if err.response["Error"]["Code"] == "ValidationException": - logger.warning( - "There's a validation error. Here's the message: %s: %s", - err.response["Error"]["Code"], - err.response["Error"]["Message"], - ) - else: - logger.error( - "Couldn't query for movies. Here's why: %s: %s", - err.response["Error"]["Code"], - err.response["Error"]["Message"], - ) - raise - else: - return response["Items"] - @@ -2678,2 +2611,0 @@ Create DynamoDB table with warm throughput setting using AWS SDK for Python (Bot - from cgitb import reset - @@ -2908,0 +2841,419 @@ The following code example shows how to create an item with TTL. +The following code example shows how to perform advanced query operations in DynamoDB. + + * Query tables using various filtering and condition techniques. + + * Implement pagination for large result sets. + + * Use Global Secondary Indexes for alternate access patterns. + + * Apply consistency controls based on application requirements. + + + + +**SDK for Python (Boto3)** + + +Query with strongly consistent reads using AWS SDK for Python (Boto3). + + + import time + + import boto3 + from boto3.dynamodb.conditions import Key + + + def query_with_consistent_read( + table_name, + partition_key_name, + partition_key_value, + sort_key_name=None, + sort_key_value=None, + consistent_read=True, + ): + """ + Query a DynamoDB table with the option for strongly consistent reads. + + Args: + table_name (str): The name of the DynamoDB table. + partition_key_name (str): The name of the partition key attribute. + partition_key_value (str): The value of the partition key to query. + sort_key_name (str, optional): The name of the sort key attribute. + sort_key_value (str, optional): The value of the sort key to query. + consistent_read (bool, optional): Whether to use strongly consistent reads. Defaults to True. + + Returns: + dict: The response from DynamoDB containing the query results. + """ + # Initialize the DynamoDB resource + dynamodb = boto3.resource("dynamodb") + table = dynamodb.Table(table_name) + + # Build the key condition expression