mysql jdbc demo_executeUpdate

package cn.test;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class connectionDB {
	public static void main(String[] args) {
		Connection conn = null;
		Statement st = null;
		ResultSet rs = null;
		// mysql的加载JDBC驱动程序
		try {
			Class.forName("com.mysql.jdbc.Driver");
		} catch (ClassNotFoundException e) {
			System.out.println("驱动加载错误");
			e.printStackTrace();
		}
		// 与mysql数据库建立连接
		try {
			conn = DriverManager.getConnection(
					"jdbc:mysql://localhost:3306/sva_rec", "root", "mysql");
		} catch (SQLException e) {
			System.out.println("数据库链接错误");
			e.printStackTrace();
		}
		// 创建Statement
		try {
			st = conn.createStatement();
			// 创建一个JDBC声明
			for (int i = 1; i < 13; i++) {
				for (int j = 1; j < 31; j++) {
					String sql = "INSERT INTO date_drv (YEAR,MONTH,dt) VALUES('2012','"+i+"','"+j+"')";
					st.executeUpdate(sql);
				}
			}
		} catch (SQLException e1) {
			System.out.println("数据操作错误");
			e1.printStackTrace();
		}
		// 关闭数据库
		try {
			if (rs != null) {
				rs.close();
				rs = null;
			}
			if (st != null) {
				st.close();
				st = null;
			}
			if (conn != null) {
				conn.close();
				conn = null;
			}
		} catch (Exception e) {
			System.out.println("数据库关闭错误");
			e.printStackTrace();
		}
	}
}