Java操作数据库

简单建立连接并查询

import java.sql.*;

public class dbtest
{
public static void main(String[] args)
{
dbtest ora = new dbtest();
}

public dbtest()
{
Connection con = null;
PreparedStatement pre = null;
ResultSet res = null;
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
System.out.println("开始尝试连接数据库！");
String url = "jdbc:oracle:thin:@127.0.0.1:1521:XE";
String user = "cashier_01";
String password = "cashier";
con = DriverManager.getConnection(url, user, password);
System.out.println("连接成功！");
}catch (Exception e){
System.out.println("连接失败！");
System.out.println(e);
}
if (con != null){
try{
System.out.println("SQL结果如下：");
String sql = "select * from manager_01.mem_card where cname = ?";
pre = con.prepareStatement(sql);
pre.setString(1, "小蔡");
res = pre.executeQuery();
while (res.next())
System.out.println("卡号:" + res.getInt("cno")
+ "\t姓名:" + res.getString("cname")
+ "\t积分:" + res.getString("point"));
}catch(Exception e){
System.out.println("SQL语句有误！");
System.out.println(e);
}
}
else
System.out.println("连接未建立！");
try {
if (res != null)    res.close();
if (pre != null)    pre.close();
if (con != null)    con.close();
System.out.println("数据库连接已关闭！");
} catch (Exception e) {
e.printStackTrace();
}
}

}

获取当前时间并插入数据库

int cardNumber = 10;
String sqlstr = null;
PreparedStatement pre = null;
Timestamp createDate = new Timestamp((new java.util.Date()).getTime());
try {
sqlstr = "insert into manager_01.mem_card(cno, cname, cdate, point) values(?, ?, ?, 0)";
pre = db.con.prepareStatement(sqlstr);
pre.setInt(1, cardNumber);
pre.setString(2, "路人甲");
pre.setTimestamp(3, createDate);
pre.execute();
} catch (Exception e) {
System.out.println(e);
e.printStackTrace();
} finally {
try {
if (pre != null)
pre.close();
} catch (Exception e2) {
System.out.println(e2);
e2.printStackTrace();
}
}