<Errors>
<Error>
<Code>missing_service_parameter</code>
<message>Your request is missing the Service parameter. Please add the
Service parameter to your request and retry. Valid values for the Service
parameter include AWSEcommerceService.</message>
</Error>
</Errors>
The more difficult error to assess is a request that is valid, that is processed, but contains an error in logic.
For example, a request might use default values such that only items in new condition are returned when
the requester meant to return items in all conditions.
The remainder of the Request Validation segment is a subsection named after the operation used in the
request. In this example, the subsection is named
ItemLookup
Request. This subsection echoes the
parameter values used in the request. These values are returned for the purpose of troubleshooting the
request.
Item Attributes Segment
Assuming that your request is valid, the final segment of the response that contains the item attributes
is typically the part of the response that contains the most value. This segment contains all of the descriptive
information about the items that satisfied the request. In the preceding example, one item was found that
satisfied the search criteria. Many attributes are returned that describe that item, including, the title,
"Saving Miss Oliver's: A Novel of Leadership, Loyalty and Change."
The item attributes returned in a response vary according to the response group used and the items
found. Merchants do not always provide Amazon with a single set of item attributes. For example, one
merchant might supply the name of a book's publisher, another might not. A response contain both of
these books would therefore contain a different set of item attributes. Item attributes that do not have
values are not returned. The API Reference Guide describes the item attributes that can be returned by
each response group.
Paging and Sorting Through Responses
Topics
•
Paging Through Results (p. 81)
•
Sorting Results (p. 83)
The only drawback of having so many items at your fingertips is the possibility of receiving too many in
a response. Product Advertising API handles this problem in several ways:
• Results are returned on page, generally, up to ten results per page
• The Sort parameter orders results
Paging Through Results
It is possible to create a request that returns many thousands of items in a response. This is problematic
for several reasons. Returning all of the item attributes for those items would dramatically impact the
performance of Product Advertising API in a negative way. Also, posting a thousand responses on a web
page is impractical.
For that reason, Product Advertising API developed the strategy of returning results a little at a time. The
good news is that you can return any page of results. For example, the first request can return the last
API Version 2011-08-01
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Product Advertising API Developer Guide
Paging and Sorting Through Responses
