Congressional Roll Call Vote – The Documents (XQuery) we looked at the initial elements found in FINAL VOTE RESULTS FOR ROLL CALL 705. Today we continue our examination of those elements, starting with <vote-data>.
As before, use ctrl-u in your browser to display the XML source for that page. Look for </vote-metadata>, the next element is <vote-data>, which contains all the votes cast by members of Congress as follows:
<recorded-vote>
<legislator name-id=”A000374″ sort-field=”Abraham” unaccented-name=”Abraham” party=”R” state=”LA” role=”legislator”>Abraham</legislator><
vote>Nay</vote>
</recorded-vote>
<recorded-vote>
<legislator name-id=”A000370″ sort-field=”Adams” unaccented-name=”Adams” party=”D” state=”NC” role=”legislator”>Adams</legislator>
<vote>Yea</vote>
</recorded-vote>
…
These are only the first two (2) lines but only the content of other <recorded-vote> elements varies from these.
I have introduced line returns to make it clear that <recorded-vote> … </recorded-vote> begin and end each record. Also note that <legislator> and <vote> are siblings.
What you didn’t see in the upper part of this document were the attributes that appear inside the <legislator> element.
Some of the attributes are: name-id=”A000374,” state=”LA” role=”legislator.”
In an XQuery, we address attributes by writing out the path to the element containing the attributes and then appending the attribute.
For example, for name-id=”A000374,” we could write:
rollcall-vote/vote-data/recorded-vote/legislator[@name-id = "A000374]
If we wanted to select that attribute value and/or the <legislator> element with that attribute and value.
Recalling that:
rollcall-vote – Root element of the document.
vote-data – Direct child of the root element.
recorded-vote – Direct child of the vote-data element (with many siblings).
legislator – Direct child of recorded-vote.
@name-id – One of the attributes of legislator.
As I mentioned in our last post, there are other ways to access elements and attributes but many useful things can be done with direct descendant XPaths.
In preparation for our next post, trying searching for “A000374” and limiting your search to the domain, congress.gov.
It is a good practice to search on unfamiliar attribute values. You never know what you may find!
Until next time!