view example/SQLcopyinto.java @ 62:b66003555560 embedded

Split parsers and cleaned the MCL layer.
author Pedro Ferreira <pedro.ferreira@monetdbsolutions.com>
date Fri, 25 Nov 2016 12:05:10 +0100 (2016-11-25)
parents f1de7262d8d9
children 6325594f01af
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/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0.  If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * Copyright 1997 - July 2008 CWI, August 2008 - 2016 MonetDB B.V.
 */

import java.sql.*;
import java.io.*;
import java.util.*;

import nl.cwi.monetdb.mcl.io.AbstractMCLReader;
import nl.cwi.monetdb.mcl.io.AbstractMCLWriter;
import nl.cwi.monetdb.mcl.net.*;

/**
 * This example demonstrates how the MonetDB JDBC driver can facilitate
 * in performing COPY INTO sequences.  This is mainly meant to show how
 * a quick load can be performed from Java.
 *
 * @author Fabian Groffen
 */

public class SQLcopyinto {
	public static void main(String[] args) throws Exception {
		// make sure the driver is loaded
		Class.forName("nl.cwi.monetdb.jdbc.MonetDriver");
		// request a connection suitable for Monet from the driver manager
		// note that the database specifier is currently not implemented, for
		// Monet itself can't access multiple databases.
		// turn on debugging
		Connection con = DriverManager.getConnection("jdbc:monetdb://localhost/database", "monetdb", "monetdb");

		// get a statement to execute on
		Statement stmt = con.createStatement();

		String query = "CREATE TABLE example (id int, val varchar(24))";
		try {
			stmt.execute(query);
		} catch (SQLException e) {
			System.out.println(query + ": " + e.getMessage());
			System.exit(1);
		}

		// now create a connection manually to perform a load, this can
		// of course also be done simultaneously with the JDBC
		// connection being kept connected

		MapiSocket server = new MapiSocket("localhost", 50000, "monetdb", "monetdb", false, "sql", "SHA256");

		server.setDatabase("database");
		server.setLanguage("sql");

		try {
			List warning = 
				server.connect( "monetdb", "monetdb");
			if (warning != null) {
				for (Object aWarning : warning) {
					System.out.println(aWarning.toString());
				}
			}

			AbstractMCLReader in = server.getReader();
			AbstractMCLWriter out = server.getWriter();

			String error = in.waitForPrompt();
			if (error != null)
				throw new Exception(error);

			query = "COPY INTO example FROM STDIN USING DELIMITERS ',','\\n';";
			// the leading 's' is essential, since it is a protocol
			// marker that should not be omitted, likewise the
			// trailing semicolon
			out.write('s');
			out.write(query);
			out.newLine();
			for (int i = 0; i < 100; i++) {
				out.write("" + i + ",val_" + i);
				out.newLine();
			}
			out.writeLine(""); // need this one for synchronisation over flush()
			error = in.waitForPrompt();
			if (error != null)
				throw new Exception(error);
			// disconnect from server
			server.close();
		} catch (IOException e) {
			System.err.println("unable to connect: " + e.getMessage());
			System.exit(-1);
		} catch (Exception e) {
			System.err.println(e.getMessage());
			System.exit(-1);
		}

		query = "SELECT COUNT(*) FROM example";
		ResultSet rs = null;
		try {
			rs = stmt.executeQuery(query);
		} catch (SQLException e) {
			System.out.println(query + ": " + e.getMessage());
			System.exit(1);
		}
		if (rs != null && rs.next())
			System.out.println(rs.getString(1));

		// free resources, close the statement
		stmt.close();
		// close the connection with the database
		con.close();

	}
}