JDBC链接数据库

JDBC链接数据库查询语句：

 

   public boolean checkUser(User user) {
        try {
            Class.forName("oracle.jdbc.driver.OracleDriver");
            Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@//localhost:1521/orcl", "root", "root");
            String sql = "select count(*) from Use_User where username = ?";
            PreparedStatement preparedStatement = conn.prepareStatement(sql);
            preparedStatement.setString(1,user.getUserName());
            ResultSet rs = preparedStatement.executeQuery();
            rs.next();
            int count = rs.getInt(1);
            rs.close();
            preparedStatement.close();
            conn.close();
            if(count>0){
                return true;
            }
            return false;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }

 

JDBC链接数据库插入：

 

  public boolean save(User user) {
        try {
            Class.forName("oracle.jdbc.driver.OracleDriver");
            Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@//localhost:1521/orcl","root","root");
            String sql = "insert into USE_USER values (emp_sequence.nextval,?,?,?,?,?)";
            PreparedStatement preparedStatement = conn.prepareStatement(sql);
            preparedStatement.setString(1,user.getRealName());
            preparedStatement.setString(2,String.valueOf(user.getAge()));
            preparedStatement.setString(3,user.getSex());
            preparedStatement.setString(4,user.getUserName());
            preparedStatement.setString(5,user.getPassWord());
            preparedStatement.executeUpdate();
            preparedStatement.close();
            conn.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }