Mega Code Archive
A trivial example of a database query performed with JDBC
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/*
* Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 1996-2002.
* All rights reserved. Software written by Ian F. Darwin and others.
* $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* Java, the Duke mascot, and all variants of Sun's Java "steaming coffee
* cup" logo are trademarks of Sun Microsystems. Sun's, and James Gosling's,
* pioneering role in inventing and promulgating (and standardizing) the Java
* language and environment is gratefully acknowledged.
*
* The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
* inventing predecessor languages C and C++ is also gratefully acknowledged.
*/
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.SQLWarning;
import java.sql.Statement;
/** A trivial example of a database query performed with JDBC. The database
* being queried only exists locally on Windows'95; it the MS Access
* "Video Database" sample database. Note that you must select this as
* "System DSN" under the name "Video.Collection" (On '95 you
* do this from Settings->Control Panel->32Bit ODBC->System DSN)
* for this particular configuration of the demo to work.
* Other than this (see the URL below), the demo would work on
* any platform (UNIX, MS, Mac, Novell, etc.).
*
* We simply get a JDBC connection to the local Database server via ODBC,
* create a Statement from that, and a ResultSet with its Query set
* to a selection of three items from a database table, and print the
* results in a while loop as they come in from the database.
*/
public class JDBCQuery {
public static void main(String[] av) {
try {
System.out.println("Loading Driver (with Class.forName)");
// Load the jdbc-odbc bridge driver
Class.forName ("sun.jdbc.odbc.JdbcOdbcDriver");
// Enable logging
// DriverManager.setLogStream(System.err);
System.out.println("Getting Connection");
Connection conn = DriverManager.getConnection (
"jdbc:odbc:Companies",
"ian", ""); // user, passwd
// Any warnings generated by the connect?
checkForWarning(conn.getWarnings());
System.out.println("Creating Statement");
Statement stmt = conn.createStatement();
System.out.println("Executing Query");
ResultSet rs = stmt.executeQuery("SELECT * FROM Companies");
System.out.println("Retrieving Results");
int i = 0;
while (rs.next()) {
System.out.println("Retrieving Company ID");
int x = rs.getInt("CustNO");
System.out.println("Retrieving Name");
String s = rs.getString("Company");
System.out.println("ROW " + ++i + ": " +
x + "; " + s + "; " + ".");
}
rs.close(); // All done with that resultset
stmt.close(); // All done with that statement
conn.close(); // All done with that DB connection
} catch (ClassNotFoundException e) {
System.out.println("Can't load driver " + e);
} catch (SQLException e) {
System.out.println("Database access failed " + e);
}
}
// Format and print any warnings from the connection
private static void checkForWarning(SQLWarning warn) throws SQLException {
// If a SQLWarning object was given, display the
// warning messages. Note that there could be
// multiple warnings chained together
if (warn != null) {
System.out.println("*** Warning ***\n");
while (warn != null) {
System.out.println("SQLState: " +
warn.getSQLState());
System.out.println("Message: " +
warn.getMessage());
System.out.println("Vendor: " +
warn.getErrorCode());
System.out.println("");
warn = warn.getNextWarning();
}
}
}
}
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