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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