JDBC程序实例
B.1 Using SELECT import java.net.URL;
import java.sql.*;
class Select {
public static void main(String argv[]) {
try {
// Create a URL specifying an ODBC data source name.
String url = "jdbc:odbc:wombat";
// Connect to the database at that URL.
Connection con = DriverManager.getConnection(url, "kgh", "");
// Execute a SELECT statement
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("SELECT a, b, c, d, key FROM Table1");
// Step through the result rows.
System.out.println("Got results:");
while (rs.next()) {
// get the values from the current row:
int a = rs.getInt(1);
BigDecimal b = rs.getBigDecimal(2);
char c[] = rs.getString(3).tocharArray();
boolean d = rs.getBoolean(4);
String key = rs.getString(5);
// Now print out the results:
System.out.print(" key=" + key);
System.out.print(" a=" + a);
System.out.print(" b=" + b);
System.out.print(" c=");
for (int i = 0; i
System.out.print(c[i]);
}
System.out.print(" d=" + d);
System.out.print("\n");
}
stmt.close();
con.close();
} catch (java.lang.Exception ex) {
ex.printStackTrace();
}
}
}
B.2 Using UPDATE // Update a couple of rows in a database.
import java.net.URL;
import java.sql.*;
class Update {
public static void main(String argv[]) {
try {
// Create a URL specifying an ODBC data source name.
String url = "jdbc:odbc:wombat";
// Connect to the database at that URL.
Connection con = DriverManager.getConnection(url, "kgh", "");
// Create a prepared statement to update the "a" field of a
// row in the "Table1" table.
// The prepared statement takes two parameters.
PreparedStatement stmt = con.prepareStatement(
"UPDATE Table1 SET a = ? WHERE key = ?");
// First use the prepared statement to update
// the "count" row to 34.
stmt.setInt(1, 34);
stmt.setString(2, "count");
stmt.executeUpdate();
System.out.println("Updated \"count\" row OK.");
// Now use the same prepared statement to update the
// "mirror" field.
// We rebind parameter 2, but reuse the other parameter.
stmt.setString(2, "mirror");
stmt.executeUpdate();
System.out.println("Updated \"mirror\" row OK.");
stmt.close();
con.close();
} catch (java.lang.Exception ex) {
ex.printStackTrace();
}
}
}
