java连接数据库步骤

* Connection : 连接数据库并担任传送数据的任务
* Statement  : 执行SQL语句
* ResultSet  ：保存Statement执行后产生的查询结果

1.注册驱动
Class.forName（JDBC驱动类）；

2.获取数据库连接
Connection con=DriverManager.getConnection（JDBC url，数据库用户名，密码）；

3.获得 Statement对象
Statement stmt=con.createStatement();

4.执行SQL语句
ResultSet rs=stmt.executeQuery（select a，b from table）；

5.处理执行结果
while（rs.next()）{

   int x=rs.getInt（"a"）；
  String s=rs.getString（"b"）；
    *数据类型要相匹配

}

6.释放资源

1.rs.close();
2.stmt.close();
3.con.close();
*顺序倒过来依次关闭

实例：
Java使用PreparedStatement接口插入数据库信息

public class PreparedStatementDemo01 {
    public static final String DBDRIVER = "org.gjt.mm.mysql.Driver";
    public static final String DBURL = "jdbc:mysql://localhost:3306/";
    public static final String DBUSER = "root";
    public static final String DBPASS = "root";
    public static void main(String args[]) throws ParseException, ClassNotFoundException, SQLException
    {
        Connection conn = null;    //数据库连接
        PreparedStatement pstmt = null;    //数据库操作
        Statement stmt = null;
        ResultSet rs = null; //Rs接口
        String name = "黄鹏";
        String password = "1598741";
        int age = 21;
        String sex = "男";
        String birthday ="1992-04-30";
        Date temp = null;
        temp = new SimpleDateFormat("yyyy-MM-dd").parse(birthday);
        java.sql.Date bri = new java.sql.Date(temp.getTime());
        //创建数据库操作语句
        String sql1 = "CREATE DATABASE MyDemo;"; 
        //选择使用哪个数据库的语句
        String sql2 = "USE MyDemo;";
        //创建数据库表操作语句
        String sql3 = "CREATE TABLE user(name varchar(20) primary key,password  varchar(20),age int,sex varchar(10),birthday Date);";
        //查询数据库语句
        String sql5 = "select * from user;";
    
        
        
        //用PreparedStatement执行的插入语句
        String sql4 = "INSERT INTO user(name,password,age,sex,birthday) VALUES(?,?,?,?,?);";
        
        //加载驱动程序
        Class.forName(DBDRIVER);
        //连接mysql数据库
        conn = DriverManager.getConnection(DBURL,DBUSER,DBPASS);
    
        //实例化PreparedStatement
        pstmt = conn.prepareStatement(sql4);
        //设置第一个?内容
        pstmt.setString(1, name);
        //设置第二个?内容
        pstmt.setString(2, password);
        //设置第三个?内容
        pstmt.setInt(3, age);
        //设置第四个?内容
        pstmt.setString(4,sex);
        //设置第五个?内容
        pstmt.setDate(5, bri);
        //执行数据库更新，不需要sql
        


        stmt = conn.createStatement(); 
        stmt.execute(sql1);
        stmt.execute(sql2);
        stmt.execute(sql3);
        
        pstmt.executeUpdate();
        rs = stmt.executeQuery(sql5);
        //向控制台输出信息
        while(rs.next()) 
        {
            String QueryName = rs.getString("name");
            String QueryPwd = rs.getString("password");
            int QueryAge = rs.getInt("age");
            String QuerySex = rs.getString("sex");
            Date QueryDate = rs.getDate("birthday");
            System.out.println("name:"+QueryName+" pwd:"+QueryPwd+" "+QueryAge+" sex:"+QueryPwd+" date:"+QueryDate);
            
        }
        
        
        
        
    
        pstmt.close();
        conn.close();
        
        
    }
}