private void CreateTable ()
{
VirtuosoCommand cmd = new VirtuosoCommand ();
cmd.Connection = connection;
try
{
cmd.CommandText = "drop table foo";
cmd.ExecuteNonQuery ();
}
catch (Exception)
{
}
cmd.CommandText = "create table foo (id int primary key, c long varchar, nc long nvarchar, b long varbinary)";
cmd.ExecuteNonQuery ();
cmd.Dispose ();
checkTable = new DataTable ();
checkTable.Columns.Add ("id", typeof (int));
checkTable.Columns.Add ("c", typeof (string));
checkTable.Columns.Add ("nc", typeof (string));
checkTable.Columns.Add ("b", typeof (byte[]) );
}
/// <summary>
/// Executes a Non-Query SQL Command against the database
/// </summary>
/// <param name="sqlCmd">SQL Command</param>
public override void ExecuteNonQuery(string sqlCmd)
{
//Get Thread ID
int thread = Thread.CurrentThread.ManagedThreadId;
//Create the SQL Command
VirtuosoCommand cmd = new VirtuosoCommand(sqlCmd, this._dbConnections[thread]);
if (this._dbTrans[thread] != null)
{
//Add to the Transaction if required
cmd.Transaction = this._dbTrans[thread];
}
//Execute
cmd.ExecuteNonQuery();
}
/// <summary>
/// Saves a Graph into the Quad Store (Warning: Completely replaces any existing Graph with the same URI)
/// </summary>
/// <param name="g">Graph to save</param>
/// <remarks>
/// Completely replaces any previously saved Graph with the same Graph URI
/// </remarks>
public void SaveGraph(IGraph g)
{
if (g.BaseUri == null) throw new RdfStorageException("Cannot save a Graph without a Base URI to Virtuoso");
try
{
this.Open(false);
//Delete the existing Graph (if it exists)
this.ExecuteNonQuery("DELETE FROM DB.DBA.RDF_QUAD WHERE G = DB.DBA.RDF_MAKE_IID_OF_QNAME('" + g.BaseUri.ToString() + "')");
//Make a call to the TTLP() Virtuoso function
VirtuosoCommand cmd = new VirtuosoCommand();
cmd.CommandText = "DB.DBA.TTLP(@data, @base, @graph, 1)";
cmd.Parameters.Add("data", VirtDbType.VarChar);
cmd.Parameters["data"].Value = VDS.RDF.Writing.StringWriter.Write(g, new NTriplesWriter());
String baseUri = g.BaseUri.ToSafeString();
cmd.Parameters.Add("base", VirtDbType.VarChar);
cmd.Parameters.Add("graph", VirtDbType.VarChar);
cmd.Parameters["base"].Value = baseUri;
cmd.Parameters["graph"].Value = baseUri;
cmd.Connection = this._db;
int result = cmd.ExecuteNonQuery();
this.Close(false);
}
catch
{
this.Close(true);
throw;
}
}
/// <summary>
/// Updates a Graph in the Quad Store
/// </summary>
/// <param name="graphUri">Graph Uri of the Graph to update</param>
/// <param name="additions">Triples to be added</param>
/// <param name="removals">Triples to be removed</param>
public void UpdateGraph(Uri graphUri, IEnumerable<Triple> additions, IEnumerable<Triple> removals)
{
try
{
this.Open(true);
int r;
//Build the Delete Data Command
if (removals != null)
{
if (removals.Any())
{
VirtuosoCommand deleteCmd = new VirtuosoCommand();
StringBuilder delete = new StringBuilder();
delete.AppendLine("SPARQL define output:format '_JAVA_' DELETE DATA");
if (graphUri != null)
{
delete.AppendLine(" FROM <" + graphUri.ToString() + ">");
}
else
{
throw new RdfStorageException("Cannot update an unnamed Graph in a Virtuoso Store using this method - you must specify the URI of a Graph to Update");
}
delete.AppendLine("{");
foreach (Triple t in removals)
{
delete.AppendLine(t.ToString(this._formatter));
}
delete.AppendLine("}");
deleteCmd.CommandText = delete.ToString();
deleteCmd.Connection = this._db;
deleteCmd.Transaction = this._dbtrans;
r = deleteCmd.ExecuteNonQuery();
if (r < 0) throw new RdfStorageException("Virtuoso encountered an error when deleting Triples");
}
}
//Build the Insert Data Command
if (additions != null)
{
if (additions.Any())
{
VirtuosoCommand insertCmd = new VirtuosoCommand();
StringBuilder insert = new StringBuilder();
insert.AppendLine("SPARQL define output:format '_JAVA_' INSERT DATA");
if (graphUri != null)
{
insert.AppendLine(" INTO <" + graphUri.ToString() + ">");
}
else
{
throw new RdfStorageException("Cannot update an unnamed Graph in a Virtuoso Store using this method - you must specify the URI of a Graph to Update");
}
insert.AppendLine("{");
foreach (Triple t in additions)
{
insert.AppendLine(t.ToString(this._formatter));
}
insert.AppendLine("}");
insertCmd.CommandText = insert.ToString();
insertCmd.Connection = this._db;
insertCmd.Transaction = this._dbtrans;
r = insertCmd.ExecuteNonQuery();
if (r < 0) throw new RdfStorageException("Virtuoso encountered an error when inserting Triples");
}
}
this.Close(true, false);
}
catch
{
this.Close(true, true);
throw;
}
}
/// <summary>
/// Executes a Non-Query SQL Command against the database
/// </summary>
/// <param name="sqlCmd">SQL Command</param>
public void ExecuteNonQuery(string sqlCmd)
{
//Create the SQL Command
VirtuosoCommand cmd = new VirtuosoCommand(sqlCmd, this._db);
if (this._dbtrans != null)
{
//Add to the Transaction if required
cmd.Transaction = this._dbtrans;
}
//Execute
cmd.ExecuteNonQuery();
}
