+
−/*
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− * This Source Code Form is subject to the terms of the Mozilla Public
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− * License, v. 2.0.  If a copy of the MPL was not distributed with this
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− * file, You can obtain one at http://mozilla.org/MPL/2.0/.
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− *
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− * Copyright 1997 - July 2008 CWI, August 2008 - 2016 MonetDB B.V.
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− */
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−
+
−import java.sql.*;
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−
+
−/**
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− * This example assumes there exists tables a and b filled with some data.
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− * On these tables some queries are executed and the JDBC driver is tested
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− * on it's accuracy and robustness against 'users'.
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− *
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− * @author Fabian Groffen
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− */
+
−public class MJDBCTest {
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−	public static void main(String[] args) throws Exception {
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−		// make sure the driver is loaded
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−		Class.forName("nl.cwi.monetdb.jdbc.MonetDriver");
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−		// turn on debugging (disabled)
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−		//nl.cwi.monetdb.jdbc.MonetConnection.setDebug(true);
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−		Connection con = DriverManager.getConnection("jdbc:monetdb://localhost/notused", "monetdb", "monetdb");
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−		Statement st = con.createStatement();
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−		ResultSet rs;
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−
+
−		rs = st.executeQuery("SELECT a.var1, COUNT(b.id) as total FROM a, b WHERE a.var1 = b.id AND a.var1 = 'andb' GROUP BY a.var1 ORDER BY a.var1, total;");
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−		// get meta data and print columns with their type
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−		ResultSetMetaData md = rs.getMetaData();
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−		for (int i = 1; i <= md.getColumnCount(); i++) {
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−			System.out.print(md.getColumnName(i) + ":" +
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−				md.getColumnTypeName(i) + "\t");
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−		}
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−		System.out.println("");
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−		// print the data: only the first 5 rows, while there probably are
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−		// a lot more. This shouldn't cause any problems afterwards since the
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−		// result should get properly discarded on the next query
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−		for (int i = 0; rs.next() && i < 5; i++) {
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−			for (int j = 1; j <= md.getColumnCount(); j++) {
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−				System.out.print(rs.getString(j) + "\t");
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−			}
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−			System.out.println("");
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−		}
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−		
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−		// tell the driver to only return 5 rows, it can optimize on this
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−		// value, and will not fetch any more than 5 rows.
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−		st.setMaxRows(5);
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−		// we ask the database for 22 rows, while we set the JDBC driver to
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−		// 5 rows, this shouldn't be a problem at all...
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−		rs = st.executeQuery("select * from a limit 22");
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−		// read till the driver says there are no rows left
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−		for (int i = 0; rs.next(); i++) {
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−			System.out.print("[" + rs.getString("var1") + "]");
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−			System.out.print("[" + rs.getString("var2") + "]");
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−			System.out.print("[" + rs.getInt("var3") + "]");
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−			System.out.println("[" + rs.getString("var4") + "]");
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−		}
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−		
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−		// this close is not needed, should be done by next execute(Query) call
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−		// however if there can be some time between this point and the next
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−		// execute call, it is from a resource perspective better to close it.
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−		//rs.close();
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−		
+
−		// unset the row limit; 0 means as much as the database sends us
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−		st.setMaxRows(0);
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−		// we only ask 10 rows
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−		rs = st.executeQuery("select * from b limit 10;");
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−		// and simply print them
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−		while (rs.next()) {
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−			System.out.print(rs.getInt("rowid") + ", ");
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−			System.out.print(rs.getString("id") + ", ");
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−			System.out.print(rs.getInt("var1") + ", ");
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−			System.out.print(rs.getInt("var2") + ", ");
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−			System.out.print(rs.getString("var3") + ", ");
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−			System.out.println(rs.getString("var4"));
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−		}
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−		
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−		// this close is not needed, as the Statement will close the last
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−		// ResultSet around when it's closed
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−		// again, if that can take some time, it's nicer to close immediately
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−		// the reason why these closes are commented out here, is to test if
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−		// the driver really cleans up it's mess like it should
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−		//rs.close();
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−
+
−		// perform a ResultSet-less query (with no trailing ; since that should
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−		// be possible as well and is JDBC standard)
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−		// Note that this method should return the number of updated rows. This
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−		// method however always returns -1, since Monet currently doesn't
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−		// support returning the affected rows.
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−		st.executeUpdate("delete from a where var1 = 'zzzz'");
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−
+
−		// closing the connection should take care of closing all generated
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−		// statements from it...
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−		// Don't forget to do it yourself if the connection is reused or much
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−		// longer alive, since the Statement object contains a lot of things
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−		// you probably want to reclaim if you don't need them anymore.
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−		//st.close();
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−		con.close();
+
−	}
+
−}