Bring in Adrian's JDBC driver as an interface

src/interfaces/jdbc/postgresql/Statement.java

@@ -0,0 +1,306 @@
+package postgresql;
+
+import java.sql.*;
+
+/**
+ * @version 1.0 15-APR-1997
+ * @author <A HREF="mailto:adrian@hottub.org">Adrian Hall</A>
+ *
+ * A Statement object is used for executing a static SQL statement and
+ * obtaining the results produced by it.
+ *
+ * Only one ResultSet per Statement can be open at any point in time.  
+ * Therefore, if the reading of one ResultSet is interleaved with the
+ * reading of another, each must have been generated by different
+ * Statements.  All statement execute methods implicitly close a
+ * statement's current ResultSet if an open one exists.
+ *
+ * @see java.sql.Statement
+ * @see ResultSet
+ */
+public class Statement implements java.sql.Statement
+{
+	Connection connection;		// The connection who created us
+	ResultSet result = null;	// The current results
+	SQLWarning warnings = null;	// The warnings chain.
+	int maxrows = 0;		// maximum no. of rows; 0 = unlimited
+	int timeout = 0;		// The timeout for a query (not used)
+	boolean escapeProcessing = true;// escape processing flag
+
+	/**
+	 * Constructor for a Statement.  It simply sets the connection
+	 * that created us.
+	 *
+	 * @param c the Connection instantation that creates us
+	 */
+	public Statement (Connection c)
+	{
+		connection = c;
+	}
+
+	/**
+	 * Execute a SQL statement that retruns a single ResultSet
+	 *
+	 * @param sql typically a static SQL SELECT statement
+	 * @return a ResulSet that contains the data produced by the query
+	 * @exception SQLException if a database access error occurs
+	 */
+	public java.sql.ResultSet executeQuery(String sql) throws SQLException
+	{
+		this.execute(sql);
+		while (result != null && !result.reallyResultSet())
+			result = result.getNext();
+		if (result == null)
+			throw new SQLException("no results returned");
+		return result;
+	}
+
+	/**
+	 * Execute a SQL INSERT, UPDATE or DELETE statement.  In addition
+	 * SQL statements that return nothing such as SQL DDL statements
+	 * can be executed
+	 *
+	 * @param sql a SQL statement
+	 * @return either a row count, or 0 for SQL commands
+	 * @exception SQLException if a database access error occurs
+	 */
+	public int executeUpdate(String sql) throws SQLException
+	{
+		this.execute(sql);
+		if (result.reallyResultSet())
+			throw new SQLException("results returned");
+		return this.getUpdateCount();
+	}
+
+	/**
+	 * In many cases, it is desirable to immediately release a
+	 * Statement's database and JDBC resources instead of waiting
+	 * for this to happen when it is automatically closed.  The
+	 * close method provides this immediate release.
+	 *
+	 * <B>Note:</B> A Statement is automatically closed when it is 
+	 * garbage collected.  When a Statement is closed, its current 
+	 * ResultSet, if one exists, is also closed.
+	 *
+	 * @exception SQLException if a database access error occurs (why?)
+	 */
+	public void close() throws SQLException
+	{
+		result = null;
+	}
+
+	/**
+	 * The maxFieldSize limit (in bytes) is the maximum amount of
+	 * data returned for any column value; it only applies to
+	 * BINARY, VARBINARY, LONGVARBINARY, CHAR, VARCHAR and LONGVARCHAR
+	 * columns.  If the limit is exceeded, the excess data is silently
+	 * discarded.
+	 *
+	 * @return the current max column size limit; zero means unlimited
+	 * @exception SQLException if a database access error occurs
+	 */
+	public int getMaxFieldSize() throws SQLException
+	{
+		return 8192;		// We cannot change this
+	}
+
+	/**
+	 * Sets the maxFieldSize - NOT! - We throw an SQLException just
+	 * to inform them to stop doing this.
+	 *
+	 * @param max the new max column size limit; zero means unlimited
+	 * @exception SQLException if a database access error occurs
+	 */
+	public void setMaxFieldSize(int max) throws SQLException
+	{
+		throw new SQLException("Attempt to setMaxFieldSize failed - compile time default");
+	}
+
+	/**
+	 * The maxRows limit is set to limit the number of rows that
+	 * any ResultSet can contain.  If the limit is exceeded, the
+	 * excess rows are silently dropped.
+	 *
+	 * @return the current maximum row limit; zero means unlimited
+	 * @exception SQLException if a database access error occurs
+	 */
+	public int getMaxRows() throws SQLException
+	{
+		return maxrows;
+	}
+
+	/**
+	 * Set the maximum number of rows
+	 *
+	 * @param max the new max rows limit; zero means unlimited
+	 * @exception SQLException if a database access error occurs
+	 * @see getMaxRows
+	 */
+	public void setMaxRows(int max) throws SQLException
+	{
+		maxrows = max;
+	}
+
+	/**
+	 * If escape scanning is on (the default), the driver will do escape
+	 * substitution before sending the SQL to the database.  
+	 *
+	 * @param enable true to enable; false to disable
+	 * @exception SQLException if a database access error occurs
+	 */
+	public void setEscapeProcessing(boolean enable) throws SQLException
+	{
+		escapeProcessing = enable;
+	}
+
+	/**
+	 * The queryTimeout limit is the number of seconds the driver
+	 * will wait for a Statement to execute.  If the limit is
+	 * exceeded, a SQLException is thrown.
+	 *
+	 * @return the current query timeout limit in seconds; 0 = unlimited
+	 * @exception SQLException if a database access error occurs
+	 */
+	public int getQueryTimeout() throws SQLException
+	{
+		return timeout;
+	}
+
+	/**
+	 * Sets the queryTimeout limit
+	 *
+	 * @param seconds - the new query timeout limit in seconds
+	 * @exception SQLException if a database access error occurs
+	 */
+	public void setQueryTimeout(int seconds) throws SQLException
+	{
+		timeout = seconds;
+	}
+
+	/**
+	 * Cancel can be used by one thread to cancel a statement that
+	 * is being executed by another thread.  However, PostgreSQL is
+	 * a sync. sort of thing, so this really has no meaning - we 
+	 * define it as a no-op (i.e. you can't cancel, but there is no
+	 * error if you try.)
+	 *
+	 * @exception SQLException only because thats the spec.
+	 */
+	public void cancel() throws SQLException
+	{
+		// No-op
+	}
+
+	/**
+	 * The first warning reported by calls on this Statement is
+	 * returned.  A Statement's execute methods clear its SQLWarning
+	 * chain.  Subsequent Statement warnings will be chained to this
+	 * SQLWarning.
+	 *
+	 * The Warning chain is automatically cleared each time a statement
+	 * is (re)executed.
+	 *
+	 * <B>Note:</B>  If you are processing a ResultSet then any warnings
+	 * associated with ResultSet reads will be chained on the ResultSet
+	 * object.
+	 *
+	 * @return the first SQLWarning on null
+	 * @exception SQLException if a database access error occurs
+	 */
+	public SQLWarning getWarnings() throws SQLException
+	{
+		return warnings;
+	}
+
+	/**
+	 * After this call, getWarnings returns null until a new warning
+	 * is reported for this Statement.
+	 *
+	 * @exception SQLException if a database access error occurs (why?)
+	 */
+	public void clearWarnings() throws SQLException
+	{
+		warnings = null;
+	}
+
+	/**
+	 * setCursorName defines the SQL cursor name that will be used by
+	 * subsequent execute methods.  This name can then be used in SQL
+	 * positioned update/delete statements to identify the current row
+	 * in the ResultSet generated by this statement.  If a database
+	 * doesn't support positioned update/delete, this method is a
+	 * no-op.
+	 *
+	 * <B>Note:</B> By definition, positioned update/delete execution
+	 * must be done by a different Statement than the one which
+	 * generated the ResultSet being used for positioning.  Also, cursor
+	 * names must be unique within a Connection.
+	 *
+	 * We throw an additional constriction.  There can only be one
+	 * cursor active at any one time.
+	 *
+	 * @param name the new cursor name
+	 * @exception SQLException if a database access error occurs
+	 */
+	public void setCursorName(String name) throws SQLException
+	{
+		connection.setCursorName(name);
+	}
+
+	/**
+	 * Execute a SQL statement that may return multiple results. We
+	 * don't have to worry about this since we do not support multiple
+	 * ResultSets.   You can use getResultSet or getUpdateCount to 
+	 * retrieve the result.
+	 *
+	 * @param sql any SQL statement
+	 * @return true if the next result is a ResulSet, false if it is
+	 * 	an update count or there are no more results
+	 * @exception SQLException if a database access error occurs
+	 */
+	public boolean execute(String sql) throws SQLException
+	{
+		result = connection.ExecSQL(sql);
+		return (result != null && result.reallyResultSet());
+	}
+
+	/**
+	 * getResultSet returns the current result as a ResultSet.  It
+	 * should only be called once per result.
+	 *
+	 * @return the current result set; null if there are no more
+	 * @exception SQLException if a database access error occurs (why?)
+	 */
+	public java.sql.ResultSet getResultSet() throws SQLException
+	{
+		return result;
+	}
+
+	/**
+	 * getUpdateCount returns the current result as an update count,
+	 * if the result is a ResultSet or there are no more results, -1
+	 * is returned.  It should only be called once per result.
+	 *
+	 * @return the current result as an update count.
+	 * @exception SQLException if a database access error occurs
+	 */
+	public int getUpdateCount() throws SQLException
+	{
+		if (result == null) 		return -1;
+		if (result.reallyResultSet())	return -1;
+		return result.getResultCount();
+	}
+
+	/**
+	 * getMoreResults moves to a Statement's next result.  If it returns
+	 * true, this result is a ResulSet.
+	 *
+	 * @return true if the next ResultSet is valid
+	 * @exception SQLException if a database access error occurs
+	 */
+	public boolean getMoreResults() throws SQLException
+	{
+		result = result.getNext();
+		return (result != null && result.reallyResultSet());
+	}
+}