From: Dan Diebolt (dandiebolt@yahoo.com)
Date: Tue Dec 04 2001 - 12:47:21 CET
I wanted to inquire about TransQuery's approach to aggregate
functions and the general handling of closure.
The expected results from the majority of queries in Use Case "R" -
(Access to Relational Data) return some type of XML table with
representation for rows/tuples/records. For example, the expected
result for Q4 (List item numbers and descriptions of items that
have no bids) is as follows:
<result>
<no_bid_item>
<itemno>1005</itemno>
<description>Tennis Racket</description>
</no_bid_item>
<no_bid_item>
<itemno>1006</itemno>
<description>Helicopter</description>
</no_bid_item>
<no_bid_item>
<itemno>1008</itemno>
<description>Broken Bicycle</description>
</no_bid_item>
</result>
This result clearly has table structure:
itemno | description
-------+---------------
1005 | Tennis Racket
1006 | Helicopter
1008 | Broken Bicycle
However, Q7 (Find the highest bid ever made for a bicycle or tricycle)
requires aggregation and its expected result is non-tabular:
<high_bid><bid>225</bid></high_bid>
I suppose you could make it tabular but wrapping it with <result>:
<result><high_bid><bid>225</bid></high_bid></result>
For *relational* queries, should TransQuery have a convention for closure
of always returning a table-like XML structure or an just an arbitrary XML
fragment? I can see a lot of benefits to insuring a table like structure
is returned in terms of styling the result into a displayable <table>.
What are peoples views on this?
__________________________________________________
Do You Yahoo!?
Buy the perfect holiday gifts at Yahoo! Shopping.
http://shopping.yahoo.com
This archive was generated by hypermail 2.1.4 : Fri Feb 22 2002 - 11:35:58 CET