Author: rvesse
Date: Mon Aug 26 17:03:33 2013
New Revision: 1517603
URL: http://svn.apache.org/r1517603
Log:
Some clean up per Stephen and Claude's comments
Modified:
jena/site/trunk/content/documentation/jdbc/index.mdtext
Modified: jena/site/trunk/content/documentation/jdbc/index.mdtext
URL:
http://svn.apache.org/viewvc/jena/site/trunk/content/documentation/jdbc/index.mdtext?rev=1517603&r1=1517602&r2=1517603&view=diff
==============================================================================
--- jena/site/trunk/content/documentation/jdbc/index.mdtext (original)
+++ jena/site/trunk/content/documentation/jdbc/index.mdtext Mon Aug 26 17:03:33
2013
@@ -4,13 +4,15 @@ Jena JDBC is a set of libraries which pr
This is a pure SPARQL over JDBC implementation, there is no attempt to present
the underlying
RDF data model as a relational model through the driver and only SPARQL
queries and updates
-are supported. Otherwise it is a fully fledge type 4 JDBC driver.
+are supported.
+
+It provides type 4 drivers in that they are pure Java based but the drivers
are not JDBC compliant since
+by definition they **do not** support SQL.
## Documentation
- [Overview](#overview)
- [Basic Usage](#basic-usage)
- - [Making Queries](#making-queries)
- [Alternatives](#alternatives)
- [Jena JDBC Drivers](drivers.html)
- [Maven Artifacts for Jena JDBC](artifacts.html)
@@ -83,7 +85,7 @@ The following takes you through the basi
to anyone who has used JDBC before and is easily used with our other
[drivers](drivers.html) simply by
changing the connection URL appropriately.
-### Making a Connection
+### Establishing a Connection
Firstly we should ensure that the driver we wish to use is registered with the
JDBC driver manager, a static
method is provided for this:
@@ -93,31 +95,36 @@ method is provided for this:
Once this is done we can then make a JDBC connection just be providing an
appropriate connection URL:
// Make a connection using the In-Memory driver starting from an empty
dataset
- Connection conn = DriverManager.getConnection("jdbc:jena:men:empty=true");
+ Connection conn = DriverManager.getConnection("jdbc:jena:mem:empty=true");
Now we can go ahead and use the connection as you would normally.
-### Making Queries
+### Performing Queries
You make queries as you would with any JDBC driver, the only difference being
that the queries must be SPARQL:
// Need a statement
Statement stmt = conn.createStatement();
- // Make a query
- ResultSet rset = stmt.executeQuery("SELECT DISTINCT ?type WHERE { ?s a
?type } LIMIT 100");
+ try {
+ // Make a query
+ ResultSet rset = stmt.executeQuery("SELECT DISTINCT ?type WHERE { ?s a
?type } LIMIT 100");
- // Iterate over results
- while (rest.next()) {
- // Print out type as a string
- System.out.println(rset.getString("type"));
- }
+ // Iterate over results
+ while (rest.next()) {
+ // Print out type as a string
+ System.out.println(rset.getString("type"));
+ }
- // Clean up
- rset.close();
- stmt.close();
+ // Clean up
+ rset.close();
+ } catch (SQLException e) {
+ System.err.println("SQL Error - " + e.getMessage());
+ } finally {
+ stmt.close();
+ }
-### Making Updates
+### Performing Updates
You make updates as you would with any JDBC driver. Again the main difference
is that updates must be SPARQL,
one downside of this is that SPARQL provides no way to indicate the number of
triples/quads affected by an update
@@ -132,11 +139,10 @@ so the JDBC driver will either return `0
System.out.println("Update succeeded");
} catch (SQLException e) {
System.out.println("Update Failed " - + e.getMessage());
+ } finally {
+ // Clean up
+ stmt.close();
}
-
- // Clean up
- rset.close();
- stmt.close();
## Alternatives
