October 23, 2013
Unit 1 = bag of words
Unit 2 = relationships
SELECT column_name,column_name FROM table_name WHERE column_name operator value;
SELECT * FROM students WHERE year='2020';
<lg type="sestina"> <lg type="sestet" rhyme="ababab"> <l>I saw my soul at rest upon a <rhyme label="a" xml:id="A">day</rhyme></l> <l>As a bird sleeping in the nest of <rhyme label="b" xml:id="B">night</rhyme>,</l> <l>Among soft leaves that give the starlight <rhyme label="a" xml:id="C">way</rhyme></l> <l>To touch its wings but not its eyes with <rhyme label="b" xml:id="D">light</rhyme>;</l> <l>So that it knew as one in visions <rhyme label="a" xml:id="E">may</rhyme>,</l> <l>And knew not as men waking, of <rhyme label="b" xml:id="F">delight</rhyme>.</l> </lg>
<html prefix="og: http://ogp.me/ns#"> <head> <title>The Rock (1996)</title> <meta property="og:title" content="The Rock" /> <meta property="og:type" content="video.movie" /> <meta property="og:url" content="http://www.imdb.com/title/tt0117500/" /> <meta property="og:image" content="http://ia.media-imdb.com/images/rock.jpg" /> ... </head> ... </html>
Subject > Predicate > Object
Luke > knows > Luke
Resource Description Framework (RDF) extends the linking structure of the Web to use URIs to name the relationship between things as well as the two ends of the link (this is usually referred to as a “triple”). Using this simple model, it allows structured and semi-structured data to be mixed, exposed, and shared across different applications.
This linking structure forms a directed, labeled graph, where the edges represent the named link between two resources, represented by the graph nodes. This graph view is the easiest possible mental model for RDF and is often used in easy-to-understand visual explanations.