:doc:`Table <index>` / Action / query

*****
query
*****



.. py:method:: DynamoDB.Table.query(**kwargs)

  

  You must provide the name of the partition key attribute and a single value for that attribute. ``Query`` returns all items with that partition key value. Optionally, you can provide a sort key attribute and use a comparison operator to refine the search results.

   

  Use the ``KeyConditionExpression`` parameter to provide a specific value for the partition key. The ``Query`` operation will return all of the items from the table or index with that partition key value. You can optionally narrow the scope of the ``Query`` operation by specifying a sort key value and a comparison operator in ``KeyConditionExpression``. To further refine the ``Query`` results, you can optionally provide a ``FilterExpression``. A ``FilterExpression`` determines which items within the results should be returned to you. All of the other results are discarded.

   

  A ``Query`` operation always returns a result set. If no matching items are found, the result set will be empty. Queries that do not return results consume the minimum number of read capacity units for that type of read operation.

   

  .. note::

    

    DynamoDB calculates the number of read capacity units consumed based on item size, not on the amount of data that is returned to an application. The number of capacity units consumed will be the same whether you request all of the attributes (the default behavior) or just some of them (using a projection expression). The number will also be the same whether or not you use a ``FilterExpression``.

    

   

  ``Query`` results are always sorted by the sort key value. If the data type of the sort key is Number, the results are returned in numeric order; otherwise, the results are returned in order of UTF-8 bytes. By default, the sort order is ascending. To reverse the order, set the ``ScanIndexForward`` parameter to false.

   

  A single ``Query`` operation will read up to the maximum number of items set (if using the ``Limit`` parameter) or a maximum of 1 MB of data and then apply any filtering to the results using ``FilterExpression``. If ``LastEvaluatedKey`` is present in the response, you will need to paginate the result set. For more information, see `Paginating the Results <https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Query.html#Query.Pagination>`__ in the *Amazon DynamoDB Developer Guide*.

   

  ``FilterExpression`` is applied after a ``Query`` finishes, but before the results are returned. A ``FilterExpression`` cannot contain partition key or sort key attributes. You need to specify those attributes in the ``KeyConditionExpression``.

   

  .. note::

    

    A ``Query`` operation can return an empty result set and a ``LastEvaluatedKey`` if all the items read for the page of results are filtered out.

    

   

  You can query a table, a local secondary index, or a global secondary index. For a query on a table or on a local secondary index, you can set the ``ConsistentRead`` parameter to ``true`` and obtain a strongly consistent result. Global secondary indexes support eventually consistent reads only, so do not specify ``ConsistentRead`` when querying a global secondary index.

  

  See also: `AWS API Documentation <https://docs.aws.amazon.com/goto/WebAPI/dynamodb-2012-08-10/Query>`_  


  **Request Syntax**
  ::

    response = table.query(
        IndexName='string',
        Select='ALL_ATTRIBUTES'|'ALL_PROJECTED_ATTRIBUTES'|'SPECIFIC_ATTRIBUTES'|'COUNT',
        AttributesToGet=[
            'string',
        ],
        Limit=123,
        ConsistentRead=True|False,
        KeyConditions={
            'string': {
                'AttributeValueList': [
                    'string'|123|Binary(b'bytes')|True|None|set(['string'])|set([123])|set([Binary(b'bytes')])|[]|{},
                ],
                'ComparisonOperator': 'EQ'|'NE'|'IN'|'LE'|'LT'|'GE'|'GT'|'BETWEEN'|'NOT_NULL'|'NULL'|'CONTAINS'|'NOT_CONTAINS'|'BEGINS_WITH'
            }
        },
        QueryFilter={
            'string': {
                'AttributeValueList': [
                    'string'|123|Binary(b'bytes')|True|None|set(['string'])|set([123])|set([Binary(b'bytes')])|[]|{},
                ],
                'ComparisonOperator': 'EQ'|'NE'|'IN'|'LE'|'LT'|'GE'|'GT'|'BETWEEN'|'NOT_NULL'|'NULL'|'CONTAINS'|'NOT_CONTAINS'|'BEGINS_WITH'
            }
        },
        ConditionalOperator='AND'|'OR',
        ScanIndexForward=True|False,
        ExclusiveStartKey={
            'string': 'string'|123|Binary(b'bytes')|True|None|set(['string'])|set([123])|set([Binary(b'bytes')])|[]|{}
        },
        ReturnConsumedCapacity='INDEXES'|'TOTAL'|'NONE',
        ProjectionExpression='string',
        FilterExpression=Attr('myattribute').eq('myvalue'),
        KeyConditionExpression=Key('mykey').eq('myvalue'),
        ExpressionAttributeNames={
            'string': 'string'
        },
        ExpressionAttributeValues={
            'string': 'string'|123|Binary(b'bytes')|True|None|set(['string'])|set([123])|set([Binary(b'bytes')])|[]|{}
        }
    )
    
  :type IndexName: string
  :param IndexName: 

    The name of an index to query. This index can be any local secondary index or global secondary index on the table. Note that if you use the ``IndexName`` parameter, you must also provide ``TableName.``

    

  
  :type Select: string
  :param Select: 

    The attributes to be returned in the result. You can retrieve all item attributes, specific item attributes, the count of matching items, or in the case of an index, some or all of the attributes projected into the index.

     

    
    * ``ALL_ATTRIBUTES`` - Returns all of the item attributes from the specified table or index. If you query a local secondary index, then for each matching item in the index, DynamoDB fetches the entire item from the parent table. If the index is configured to project all item attributes, then all of the data can be obtained from the local secondary index, and no fetching is required.
     
    * ``ALL_PROJECTED_ATTRIBUTES`` - Allowed only when querying an index. Retrieves all attributes that have been projected into the index. If the index is configured to project all attributes, this return value is equivalent to specifying ``ALL_ATTRIBUTES``.
     
    * ``COUNT`` - Returns the number of matching items, rather than the matching items themselves. Note that this uses the same quantity of read capacity units as getting the items, and is subject to the same item size calculations.
     
    * ``SPECIFIC_ATTRIBUTES`` - Returns only the attributes listed in ``ProjectionExpression``. This return value is equivalent to specifying ``ProjectionExpression`` without specifying any value for ``Select``. If you query or scan a local secondary index and request only attributes that are projected into that index, the operation will read only the index and not the table. If any of the requested attributes are not projected into the local secondary index, DynamoDB fetches each of these attributes from the parent table. This extra fetching incurs additional throughput cost and latency. If you query or scan a global secondary index, you can only request attributes that are projected into the index. Global secondary index queries cannot fetch attributes from the parent table.
    

     

    If neither ``Select`` nor ``ProjectionExpression`` are specified, DynamoDB defaults to ``ALL_ATTRIBUTES`` when accessing a table, and ``ALL_PROJECTED_ATTRIBUTES`` when accessing an index. You cannot use both ``Select`` and ``ProjectionExpression`` together in a single request, unless the value for ``Select`` is ``SPECIFIC_ATTRIBUTES``. (This usage is equivalent to specifying ``ProjectionExpression`` without any value for ``Select``.)

     

    .. note::

      

      If you use the ``ProjectionExpression`` parameter, then the value for ``Select`` can only be ``SPECIFIC_ATTRIBUTES``. Any other value for ``Select`` will return an error.

      

    

  
  :type AttributesToGet: list
  :param AttributesToGet: 

    This is a legacy parameter. Use ``ProjectionExpression`` instead. For more information, see `AttributesToGet <https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.AttributesToGet.html>`__ in the *Amazon DynamoDB Developer Guide*.

    

  
    - *(string) --* 

    

  :type Limit: integer
  :param Limit: 

    The maximum number of items to evaluate (not necessarily the number of matching items). If DynamoDB processes the number of items up to the limit while processing the results, it stops the operation and returns the matching values up to that point, and a key in ``LastEvaluatedKey`` to apply in a subsequent operation, so that you can pick up where you left off. Also, if the processed dataset size exceeds 1 MB before DynamoDB reaches this limit, it stops the operation and returns the matching values up to the limit, and a key in ``LastEvaluatedKey`` to apply in a subsequent operation to continue the operation. For more information, see `Query and Scan <https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/QueryAndScan.html>`__ in the *Amazon DynamoDB Developer Guide*.

    

  
  :type ConsistentRead: boolean
  :param ConsistentRead: 

    Determines the read consistency model: If set to ``true``, then the operation uses strongly consistent reads; otherwise, the operation uses eventually consistent reads.

     

    Strongly consistent reads are not supported on global secondary indexes. If you query a global secondary index with ``ConsistentRead`` set to ``true``, you will receive a ``ValidationException``.

    

  
  :type KeyConditions: dict
  :param KeyConditions: 

    This is a legacy parameter. Use ``KeyConditionExpression`` instead. For more information, see `KeyConditions <https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.KeyConditions.html>`__ in the *Amazon DynamoDB Developer Guide*.

    

  
    - *(string) --* 

    
      - *(dict) --* 

        Represents the selection criteria for a ``Query`` or ``Scan`` operation:

         

        
        * For a ``Query`` operation, ``Condition`` is used for specifying the ``KeyConditions`` to use when querying a table or an index. For ``KeyConditions``, only the following comparison operators are supported: ``EQ | LE | LT | GE | GT | BEGINS_WITH | BETWEEN`` ``Condition`` is also used in a ``QueryFilter``, which evaluates the query results and returns only the desired values.
         
        * For a ``Scan`` operation, ``Condition`` is used in a ``ScanFilter``, which evaluates the scan results and returns only the desired values.
        

        

      
        - **AttributeValueList** *(list) --* 

          One or more values to evaluate against the supplied attribute. The number of values in the list depends on the ``ComparisonOperator`` being used.

           

          For type Number, value comparisons are numeric.

           

          String value comparisons for greater than, equals, or less than are based on ASCII character code values. For example, ``a`` is greater than ``A``, and ``a`` is greater than ``B``. For a list of code values, see `http\://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters <http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters>`__.

           

          For Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values.

          

        
          - *(valid DynamoDB type) -- *- The value of the attribute. The valid value types are listed in the :ref:`DynamoDB Reference Guide<ref_valid_dynamodb_types>`.

          
          
      
        - **ComparisonOperator** *(string) --* **[REQUIRED]** 

          A comparator for evaluating attributes. For example, equals, greater than, less than, etc.

           

          The following comparison operators are available:

           

          ``EQ | NE | LE | LT | GE | GT | NOT_NULL | NULL | CONTAINS | NOT_CONTAINS | BEGINS_WITH | IN | BETWEEN``

           

          The following are descriptions of each comparison operator.

           

          
          * ``EQ`` : Equal. ``EQ`` is supported for all data types, including lists and maps. ``AttributeValueList`` can contain only one ``AttributeValue`` element of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an ``AttributeValue`` element of a different type than the one provided in the request, the value does not match. For example, ``{"S":"6"}`` does not equal ``{"N":"6"}``. Also, ``{"N":"6"}`` does not equal ``{"NS":["6", "2", "1"]}``.
           
          * ``NE`` : Not equal. ``NE`` is supported for all data types, including lists and maps. ``AttributeValueList`` can contain only one ``AttributeValue`` of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an ``AttributeValue`` of a different type than the one provided in the request, the value does not match. For example, ``{"S":"6"}`` does not equal ``{"N":"6"}``. Also, ``{"N":"6"}`` does not equal ``{"NS":["6", "2", "1"]}``.
           
          * ``LE`` : Less than or equal. ``AttributeValueList`` can contain only one ``AttributeValue`` element of type String, Number, or Binary (not a set type). If an item contains an ``AttributeValue`` element of a different type than the one provided in the request, the value does not match. For example, ``{"S":"6"}`` does not equal ``{"N":"6"}``. Also, ``{"N":"6"}`` does not compare to ``{"NS":["6", "2", "1"]}``.
           
          * ``LT`` : Less than. ``AttributeValueList`` can contain only one ``AttributeValue`` of type String, Number, or Binary (not a set type). If an item contains an ``AttributeValue`` element of a different type than the one provided in the request, the value does not match. For example, ``{"S":"6"}`` does not equal ``{"N":"6"}``. Also, ``{"N":"6"}`` does not compare to ``{"NS":["6", "2", "1"]}``.
           
          * ``GE`` : Greater than or equal. ``AttributeValueList`` can contain only one ``AttributeValue`` element of type String, Number, or Binary (not a set type). If an item contains an ``AttributeValue`` element of a different type than the one provided in the request, the value does not match. For example, ``{"S":"6"}`` does not equal ``{"N":"6"}``. Also, ``{"N":"6"}`` does not compare to ``{"NS":["6", "2", "1"]}``.
           
          * ``GT`` : Greater than. ``AttributeValueList`` can contain only one ``AttributeValue`` element of type String, Number, or Binary (not a set type). If an item contains an ``AttributeValue`` element of a different type than the one provided in the request, the value does not match. For example, ``{"S":"6"}`` does not equal ``{"N":"6"}``. Also, ``{"N":"6"}`` does not compare to ``{"NS":["6", "2", "1"]}``.
           
          * ``NOT_NULL`` : The attribute exists. ``NOT_NULL`` is supported for all data types, including lists and maps. 

          .. note::

            This operator tests for the existence of an attribute, not its data type. If the data type of attribute " ``a``" is null, and you evaluate it using ``NOT_NULL``, the result is a Boolean ``true``. This result is because the attribute " ``a``" exists; its data type is not relevant to the ``NOT_NULL`` comparison operator.

          
           
          * ``NULL`` : The attribute does not exist. ``NULL`` is supported for all data types, including lists and maps. 

          .. note::

            This operator tests for the nonexistence of an attribute, not its data type. If the data type of attribute " ``a``" is null, and you evaluate it using ``NULL``, the result is a Boolean ``false``. This is because the attribute " ``a``" exists; its data type is not relevant to the ``NULL`` comparison operator.

          
           
          * ``CONTAINS`` : Checks for a subsequence, or value in a set. ``AttributeValueList`` can contain only one ``AttributeValue`` element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is of type String, then the operator checks for a substring match. If the target attribute of the comparison is of type Binary, then the operator looks for a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" ``SS``", " ``NS``", or " ``BS``"), then the operator evaluates to true if it finds an exact match with any member of the set. CONTAINS is supported for lists: When evaluating " ``a CONTAINS b``", " ``a``" can be a list; however, " ``b``" cannot be a set, a map, or a list.
           
          * ``NOT_CONTAINS`` : Checks for absence of a subsequence, or absence of a value in a set. ``AttributeValueList`` can contain only one ``AttributeValue`` element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is a String, then the operator checks for the absence of a substring match. If the target attribute of the comparison is Binary, then the operator checks for the absence of a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" ``SS``", " ``NS``", or " ``BS``"), then the operator evaluates to true if it *does not* find an exact match with any member of the set. NOT_CONTAINS is supported for lists: When evaluating " ``a NOT CONTAINS b``", " ``a``" can be a list; however, " ``b``" cannot be a set, a map, or a list.
           
          * ``BEGINS_WITH`` : Checks for a prefix. ``AttributeValueList`` can contain only one ``AttributeValue`` of type String or Binary (not a Number or a set type). The target attribute of the comparison must be of type String or Binary (not a Number or a set type).
           
          * ``IN`` : Checks for matching elements in a list. ``AttributeValueList`` can contain one or more ``AttributeValue`` elements of type String, Number, or Binary. These attributes are compared against an existing attribute of an item. If any elements of the input are equal to the item attribute, the expression evaluates to true.
           
          * ``BETWEEN`` : Greater than or equal to the first value, and less than or equal to the second value. ``AttributeValueList`` must contain two ``AttributeValue`` elements of the same type, either String, Number, or Binary (not a set type). A target attribute matches if the target value is greater than, or equal to, the first element and less than, or equal to, the second element. If an item contains an ``AttributeValue`` element of a different type than the one provided in the request, the value does not match. For example, ``{"S":"6"}`` does not compare to ``{"N":"6"}``. Also, ``{"N":"6"}`` does not compare to ``{"NS":["6", "2", "1"]}``
          

           

          For usage examples of ``AttributeValueList`` and ``ComparisonOperator``, see `Legacy Conditional Parameters <https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.html>`__ in the *Amazon DynamoDB Developer Guide*.

          

        
      


  :type QueryFilter: dict
  :param QueryFilter: 

    This is a legacy parameter. Use ``FilterExpression`` instead. For more information, see `QueryFilter <https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.QueryFilter.html>`__ in the *Amazon DynamoDB Developer Guide*.

    

  
    - *(string) --* 

    
      - *(dict) --* 

        Represents the selection criteria for a ``Query`` or ``Scan`` operation:

         

        
        * For a ``Query`` operation, ``Condition`` is used for specifying the ``KeyConditions`` to use when querying a table or an index. For ``KeyConditions``, only the following comparison operators are supported: ``EQ | LE | LT | GE | GT | BEGINS_WITH | BETWEEN`` ``Condition`` is also used in a ``QueryFilter``, which evaluates the query results and returns only the desired values.
         
        * For a ``Scan`` operation, ``Condition`` is used in a ``ScanFilter``, which evaluates the scan results and returns only the desired values.
        

        

      
        - **AttributeValueList** *(list) --* 

          One or more values to evaluate against the supplied attribute. The number of values in the list depends on the ``ComparisonOperator`` being used.

           

          For type Number, value comparisons are numeric.

           

          String value comparisons for greater than, equals, or less than are based on ASCII character code values. For example, ``a`` is greater than ``A``, and ``a`` is greater than ``B``. For a list of code values, see `http\://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters <http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters>`__.

           

          For Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values.

          

        
          - *(valid DynamoDB type) -- *- The value of the attribute. The valid value types are listed in the :ref:`DynamoDB Reference Guide<ref_valid_dynamodb_types>`.

          
          
      
        - **ComparisonOperator** *(string) --* **[REQUIRED]** 

          A comparator for evaluating attributes. For example, equals, greater than, less than, etc.

           

          The following comparison operators are available:

           

          ``EQ | NE | LE | LT | GE | GT | NOT_NULL | NULL | CONTAINS | NOT_CONTAINS | BEGINS_WITH | IN | BETWEEN``

           

          The following are descriptions of each comparison operator.

           

          
          * ``EQ`` : Equal. ``EQ`` is supported for all data types, including lists and maps. ``AttributeValueList`` can contain only one ``AttributeValue`` element of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an ``AttributeValue`` element of a different type than the one provided in the request, the value does not match. For example, ``{"S":"6"}`` does not equal ``{"N":"6"}``. Also, ``{"N":"6"}`` does not equal ``{"NS":["6", "2", "1"]}``.
           
          * ``NE`` : Not equal. ``NE`` is supported for all data types, including lists and maps. ``AttributeValueList`` can contain only one ``AttributeValue`` of type String, Number, Binary, String Set, Number Set, or Binary Set. If an item contains an ``AttributeValue`` of a different type than the one provided in the request, the value does not match. For example, ``{"S":"6"}`` does not equal ``{"N":"6"}``. Also, ``{"N":"6"}`` does not equal ``{"NS":["6", "2", "1"]}``.
           
          * ``LE`` : Less than or equal. ``AttributeValueList`` can contain only one ``AttributeValue`` element of type String, Number, or Binary (not a set type). If an item contains an ``AttributeValue`` element of a different type than the one provided in the request, the value does not match. For example, ``{"S":"6"}`` does not equal ``{"N":"6"}``. Also, ``{"N":"6"}`` does not compare to ``{"NS":["6", "2", "1"]}``.
           
          * ``LT`` : Less than. ``AttributeValueList`` can contain only one ``AttributeValue`` of type String, Number, or Binary (not a set type). If an item contains an ``AttributeValue`` element of a different type than the one provided in the request, the value does not match. For example, ``{"S":"6"}`` does not equal ``{"N":"6"}``. Also, ``{"N":"6"}`` does not compare to ``{"NS":["6", "2", "1"]}``.
           
          * ``GE`` : Greater than or equal. ``AttributeValueList`` can contain only one ``AttributeValue`` element of type String, Number, or Binary (not a set type). If an item contains an ``AttributeValue`` element of a different type than the one provided in the request, the value does not match. For example, ``{"S":"6"}`` does not equal ``{"N":"6"}``. Also, ``{"N":"6"}`` does not compare to ``{"NS":["6", "2", "1"]}``.
           
          * ``GT`` : Greater than. ``AttributeValueList`` can contain only one ``AttributeValue`` element of type String, Number, or Binary (not a set type). If an item contains an ``AttributeValue`` element of a different type than the one provided in the request, the value does not match. For example, ``{"S":"6"}`` does not equal ``{"N":"6"}``. Also, ``{"N":"6"}`` does not compare to ``{"NS":["6", "2", "1"]}``.
           
          * ``NOT_NULL`` : The attribute exists. ``NOT_NULL`` is supported for all data types, including lists and maps. 

          .. note::

            This operator tests for the existence of an attribute, not its data type. If the data type of attribute " ``a``" is null, and you evaluate it using ``NOT_NULL``, the result is a Boolean ``true``. This result is because the attribute " ``a``" exists; its data type is not relevant to the ``NOT_NULL`` comparison operator.

          
           
          * ``NULL`` : The attribute does not exist. ``NULL`` is supported for all data types, including lists and maps. 

          .. note::

            This operator tests for the nonexistence of an attribute, not its data type. If the data type of attribute " ``a``" is null, and you evaluate it using ``NULL``, the result is a Boolean ``false``. This is because the attribute " ``a``" exists; its data type is not relevant to the ``NULL`` comparison operator.

          
           
          * ``CONTAINS`` : Checks for a subsequence, or value in a set. ``AttributeValueList`` can contain only one ``AttributeValue`` element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is of type String, then the operator checks for a substring match. If the target attribute of the comparison is of type Binary, then the operator looks for a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" ``SS``", " ``NS``", or " ``BS``"), then the operator evaluates to true if it finds an exact match with any member of the set. CONTAINS is supported for lists: When evaluating " ``a CONTAINS b``", " ``a``" can be a list; however, " ``b``" cannot be a set, a map, or a list.
           
          * ``NOT_CONTAINS`` : Checks for absence of a subsequence, or absence of a value in a set. ``AttributeValueList`` can contain only one ``AttributeValue`` element of type String, Number, or Binary (not a set type). If the target attribute of the comparison is a String, then the operator checks for the absence of a substring match. If the target attribute of the comparison is Binary, then the operator checks for the absence of a subsequence of the target that matches the input. If the target attribute of the comparison is a set (" ``SS``", " ``NS``", or " ``BS``"), then the operator evaluates to true if it *does not* find an exact match with any member of the set. NOT_CONTAINS is supported for lists: When evaluating " ``a NOT CONTAINS b``", " ``a``" can be a list; however, " ``b``" cannot be a set, a map, or a list.
           
          * ``BEGINS_WITH`` : Checks for a prefix. ``AttributeValueList`` can contain only one ``AttributeValue`` of type String or Binary (not a Number or a set type). The target attribute of the comparison must be of type String or Binary (not a Number or a set type).
           
          * ``IN`` : Checks for matching elements in a list. ``AttributeValueList`` can contain one or more ``AttributeValue`` elements of type String, Number, or Binary. These attributes are compared against an existing attribute of an item. If any elements of the input are equal to the item attribute, the expression evaluates to true.
           
          * ``BETWEEN`` : Greater than or equal to the first value, and less than or equal to the second value. ``AttributeValueList`` must contain two ``AttributeValue`` elements of the same type, either String, Number, or Binary (not a set type). A target attribute matches if the target value is greater than, or equal to, the first element and less than, or equal to, the second element. If an item contains an ``AttributeValue`` element of a different type than the one provided in the request, the value does not match. For example, ``{"S":"6"}`` does not compare to ``{"N":"6"}``. Also, ``{"N":"6"}`` does not compare to ``{"NS":["6", "2", "1"]}``
          

           

          For usage examples of ``AttributeValueList`` and ``ComparisonOperator``, see `Legacy Conditional Parameters <https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.html>`__ in the *Amazon DynamoDB Developer Guide*.

          

        
      


  :type ConditionalOperator: string
  :param ConditionalOperator: 

    This is a legacy parameter. Use ``FilterExpression`` instead. For more information, see `ConditionalOperator <https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.ConditionalOperator.html>`__ in the *Amazon DynamoDB Developer Guide*.

    

  
  :type ScanIndexForward: boolean
  :param ScanIndexForward: 

    Specifies the order for index traversal: If ``true`` (default), the traversal is performed in ascending order; if ``false``, the traversal is performed in descending order.

     

    Items with the same partition key value are stored in sorted order by sort key. If the sort key data type is Number, the results are stored in numeric order. For type String, the results are stored in order of UTF-8 bytes. For type Binary, DynamoDB treats each byte of the binary data as unsigned.

     

    If ``ScanIndexForward`` is ``true``, DynamoDB returns the results in the order in which they are stored (by sort key value). This is the default behavior. If ``ScanIndexForward`` is ``false``, DynamoDB reads the results in reverse order by sort key value, and then returns the results to the client.

    

  
  :type ExclusiveStartKey: dict
  :param ExclusiveStartKey: 

    The primary key of the first item that this operation will evaluate. Use the value that was returned for ``LastEvaluatedKey`` in the previous operation.

     

    The data type for ``ExclusiveStartKey`` must be String, Number, or Binary. No set data types are allowed.

    

  
    - *(string) --* 

    
      - *(valid DynamoDB type) -- *- The value of the attribute. The valid value types are listed in the :ref:`DynamoDB Reference Guide<ref_valid_dynamodb_types>`.

      
      


  :type ReturnConsumedCapacity: string
  :param ReturnConsumedCapacity: 

    Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:

     

    
    * ``INDEXES`` - The response includes the aggregate ``ConsumedCapacity`` for the operation, together with ``ConsumedCapacity`` for each table and secondary index that was accessed. Note that some operations, such as ``GetItem`` and ``BatchGetItem``, do not access any indexes at all. In these cases, specifying ``INDEXES`` will only return ``ConsumedCapacity`` information for table(s).
     
    * ``TOTAL`` - The response includes only the aggregate ``ConsumedCapacity`` for the operation.
     
    * ``NONE`` - No ``ConsumedCapacity`` details are included in the response.
    

    

  
  :type ProjectionExpression: string
  :param ProjectionExpression: 

    A string that identifies one or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.

     

    If no attribute names are specified, then all attributes will be returned. If any of the requested attributes are not found, they will not appear in the result.

     

    For more information, see `Accessing Item Attributes <https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html>`__ in the *Amazon DynamoDB Developer Guide*.

    

  
  :type FilterExpression: condition from :py:class:`boto3.dynamodb.conditions.Attr` method
  :param FilterExpression: The condition(s) an attribute(s) must meet. Valid conditions are listed in the :ref:`DynamoDB Reference Guide<ref_dynamodb_conditions>`.

  
  :type KeyConditionExpression: condition from :py:class:`boto3.dynamodb.conditions.Key` method
  :param KeyConditionExpression: The condition(s) a key(s) must meet. Valid conditions are listed in the :ref:`DynamoDB Reference Guide<ref_dynamodb_conditions>`.

  
  :type ExpressionAttributeNames: dict
  :param ExpressionAttributeNames: 

    One or more substitution tokens for attribute names in an expression. The following are some use cases for using ``ExpressionAttributeNames``:

     

    
    * To access an attribute whose name conflicts with a DynamoDB reserved word.
     
    * To create a placeholder for repeating occurrences of an attribute name in an expression.
     
    * To prevent special characters in an attribute name from being misinterpreted in an expression.
    

     

    Use the **#** character in an expression to dereference an attribute name. For example, consider the following attribute name:

     

    
    * ``Percentile``
    

     

    The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see `Reserved Words <https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html>`__ in the *Amazon DynamoDB Developer Guide*). To work around this, you could specify the following for ``ExpressionAttributeNames``:

     

    
    * ``{"#P":"Percentile"}``
    

     

    You could then use this substitution in an expression, as in this example:

     

    
    * ``#P = :val``
    

     

    .. note::

      

      Tokens that begin with the **:** character are *expression attribute values*, which are placeholders for the actual value at runtime.

      

     

    For more information on expression attribute names, see `Specifying Item Attributes <https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html>`__ in the *Amazon DynamoDB Developer Guide*.

    

  
    - *(string) --* 

    
      - *(string) --* 

      


  :type ExpressionAttributeValues: dict
  :param ExpressionAttributeValues: 

    One or more values that can be substituted in an expression.

     

    Use the **:** (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the *ProductStatus* attribute was one of the following:

     

    ``Available | Backordered | Discontinued``

     

    You would first need to specify ``ExpressionAttributeValues`` as follows:

     

    ``{ ":avail":{"S":"Available"}, ":back":{"S":"Backordered"}, ":disc":{"S":"Discontinued"} }``

     

    You could then use these values in an expression, such as this:

     

    ``ProductStatus IN (:avail, :back, :disc)``

     

    For more information on expression attribute values, see `Specifying Conditions <https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.SpecifyingConditions.html>`__ in the *Amazon DynamoDB Developer Guide*.

    

  
    - *(string) --* 

    
      - *(valid DynamoDB type) -- *- The value of the attribute. The valid value types are listed in the :ref:`DynamoDB Reference Guide<ref_valid_dynamodb_types>`.

      
      


  
  :rtype: dict
  :returns: 
    
    **Response Syntax**

    
    ::

      {
          'Items': [
              {
                  'string': 'string'|123|Binary(b'bytes')|True|None|set(['string'])|set([123])|set([Binary(b'bytes')])|[]|{}
              },
          ],
          'Count': 123,
          'ScannedCount': 123,
          'LastEvaluatedKey': {
              'string': 'string'|123|Binary(b'bytes')|True|None|set(['string'])|set([123])|set([Binary(b'bytes')])|[]|{}
          },
          'ConsumedCapacity': {
              'TableName': 'string',
              'CapacityUnits': 123.0,
              'ReadCapacityUnits': 123.0,
              'WriteCapacityUnits': 123.0,
              'Table': {
                  'ReadCapacityUnits': 123.0,
                  'WriteCapacityUnits': 123.0,
                  'CapacityUnits': 123.0
              },
              'LocalSecondaryIndexes': {
                  'string': {
                      'ReadCapacityUnits': 123.0,
                      'WriteCapacityUnits': 123.0,
                      'CapacityUnits': 123.0
                  }
              },
              'GlobalSecondaryIndexes': {
                  'string': {
                      'ReadCapacityUnits': 123.0,
                      'WriteCapacityUnits': 123.0,
                      'CapacityUnits': 123.0
                  }
              }
          }
      }
      
    **Response Structure**

    

    - *(dict) --* 

      Represents the output of a ``Query`` operation.

      
      

      - **Items** *(list) --* 

        An array of item attributes that match the query criteria. Each element in this array consists of an attribute name and the value for that attribute.

        
        

        - *(dict) --* 
          

          - *(string) --* 
            

            - *(valid DynamoDB type) -- *- The value of the attribute. The valid value types are listed in the :ref:`DynamoDB Reference Guide<ref_valid_dynamodb_types>`.
          
      
    
    
      

      - **Count** *(integer) --* 

        The number of items in the response.

         

        If you used a ``QueryFilter`` in the request, then ``Count`` is the number of items returned after the filter was applied, and ``ScannedCount`` is the number of matching items before the filter was applied.

         

        If you did not use a filter in the request, then ``Count`` and ``ScannedCount`` are the same.

        
      

      - **ScannedCount** *(integer) --* 

        The number of items evaluated, before any ``QueryFilter`` is applied. A high ``ScannedCount`` value with few, or no, ``Count`` results indicates an inefficient ``Query`` operation. For more information, see `Count and ScannedCount <https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Scan.html#Scan.Count>`__ in the *Amazon DynamoDB Developer Guide*.

         

        If you did not use a filter in the request, then ``ScannedCount`` is the same as ``Count``.

        
      

      - **LastEvaluatedKey** *(dict) --* 

        The primary key of the item where the operation stopped, inclusive of the previous result set. Use this value to start a new operation, excluding this value in the new request.

         

        If ``LastEvaluatedKey`` is empty, then the "last page" of results has been processed and there is no more data to be retrieved.

         

        If ``LastEvaluatedKey`` is not empty, it does not necessarily mean that there is more data in the result set. The only way to know when you have reached the end of the result set is when ``LastEvaluatedKey`` is empty.

        
        

        - *(string) --* 
          

          - *(valid DynamoDB type) -- *- The value of the attribute. The valid value types are listed in the :ref:`DynamoDB Reference Guide<ref_valid_dynamodb_types>`.
        
    
  
      

      - **ConsumedCapacity** *(dict) --* 

        The capacity units consumed by the ``Query`` operation. The data returned includes the total provisioned throughput consumed, along with statistics for the table and any indexes involved in the operation. ``ConsumedCapacity`` is only returned if the ``ReturnConsumedCapacity`` parameter was specified. For more information, see `Capacity unit consumption for read operations <https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/read-write-operations.html#read-operation-consumption>`__ in the *Amazon DynamoDB Developer Guide*.

        
        

        - **TableName** *(string) --* 

          The name of the table that was affected by the operation. If you had specified the Amazon Resource Name (ARN) of a table in the input, you'll see the table ARN in the response.

          
        

        - **CapacityUnits** *(float) --* 

          The total number of capacity units consumed by the operation.

          
        

        - **ReadCapacityUnits** *(float) --* 

          The total number of read capacity units consumed by the operation.

          
        

        - **WriteCapacityUnits** *(float) --* 

          The total number of write capacity units consumed by the operation.

          
        

        - **Table** *(dict) --* 

          The amount of throughput consumed on the table affected by the operation.

          
          

          - **ReadCapacityUnits** *(float) --* 

            The total number of read capacity units consumed on a table or an index.

            
          

          - **WriteCapacityUnits** *(float) --* 

            The total number of write capacity units consumed on a table or an index.

            
          

          - **CapacityUnits** *(float) --* 

            The total number of capacity units consumed on a table or an index.

            
      
        

        - **LocalSecondaryIndexes** *(dict) --* 

          The amount of throughput consumed on each local index affected by the operation.

          
          

          - *(string) --* 
            

            - *(dict) --* 

              Represents the amount of provisioned throughput capacity consumed on a table or an index.

              
              

              - **ReadCapacityUnits** *(float) --* 

                The total number of read capacity units consumed on a table or an index.

                
              

              - **WriteCapacityUnits** *(float) --* 

                The total number of write capacity units consumed on a table or an index.

                
              

              - **CapacityUnits** *(float) --* 

                The total number of capacity units consumed on a table or an index.

                
          
      
    
        

        - **GlobalSecondaryIndexes** *(dict) --* 

          The amount of throughput consumed on each global index affected by the operation.

          
          

          - *(string) --* 
            

            - *(dict) --* 

              Represents the amount of provisioned throughput capacity consumed on a table or an index.

              
              

              - **ReadCapacityUnits** *(float) --* 

                The total number of read capacity units consumed on a table or an index.

                
              

              - **WriteCapacityUnits** *(float) --* 

                The total number of write capacity units consumed on a table or an index.

                
              

              - **CapacityUnits** *(float) --* 

                The total number of capacity units consumed on a table or an index.

                
          
      
    
    
  