jdbc 基本语法

1.连接

  String userName="root";                    //mysql用户名
  String userPasswd="4622dqh";         //mysql密码
  String dbName="test";                        //数据库名
  String tableName="user";                   //表名
  String url="jdbc:mysql://localhost/"+dbName+"?user="+userName+"&password="+userPasswd;

  Class.forName("com.mysql.jdbc.Driver").newInstance();
  Connection connection=DriverManager.getConnection(url);

  Statement statement = connection.createStatement();

2.查询

 String sql="SELECT * FROM "+tableName;  //"sql查询语句"
 ResultSet rs = statement.executeQuery(sql);
 ResultSetMetaData rmeta = rs.getMetaData();
 int numColumns=rmeta.getColumnCount();
 out.print("id");
 out.print("|");
 out.print("num");
 out.print("<br>");


 while(rs.next()) {
   out.print(rs.getString(1)+" ");
   out.print("|");
   out.print(rs.getString(2));
   out.print("<br>");
 }

 out.print("<br>");

 out.print("数据库操作成功，恭喜你");

关闭

  rs.close();

  statement.close();

  connection.close();