jdbc之使用占位符的增删改查(二)
ss.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/mydb","root","root");
//注意★
String sql = "select id,username,address from t_user where id= ";
PreparedStatement sta = con.prepareStatement(sql);
sta.setInt(1, id);
ResultSet rs = sta.executeQuery();
//注意：当现实一条记录时：while可以换成if。★
if(rs.next()) {
int did = rs.getInt("id");
String username = rs.getString("username");
String address = rs.getString("address");
System.out.println(did + "\t" + username + "\t" + address);
}
rs.close();
sta.close();
con.close();
}
}