Question

您好我正在制作聊天应用程序。当用户滚动到顶部时，我想要显示的是显示历史/显示更多按钮，当我点击它时，应该批量加载更早的消息。由于多个用户可以聊天，我在存储获取的消息的最后一个id方面遇到问题。这是我的概念

当用户点击在线用户时，会从数据库中加载前10个消息。当用户滚动到顶部时，会出现更多按钮。如果他单击该按钮然后使用上次获取的行的id，我将再次获取下一个小于先前id的10行。但由于有多个用户，我需要存储不同的ID。我该怎么做这是我的jquery和php代码。

$('#m-'+id).scroll(function() {

                    var pos = $('#m-'+id).scrollTop();
                    if (pos == 0) {
                        $("#h2-"+id).after("<div id = 'showmore-"+id+"'>Show More</div>");
                    }
                    else{
                        $("#showmore-"+id).hide();
                    }

                    $("#showmore-"+id).click(function(){
                            $.ajax({

                            url: "loadmessage.php",
                            type: "POST",
                            data:{
                                'sender': sender,
                                'receiver': receiver,
                            },
                            //SELECT * FROM `messagse` WHERE ((sender_id = 1 AND receiver_id = 2) OR (sender_id = 1 AND receiver_id = 2)) AND (id < 36) order by id desc LIMIT 20
                            success: function(response){
                                var result = JSON.parse(response);
                                console.log("Result is " +result);
                                //result.sort();

                                for(var i = result.length-1; i >=0; i--){
                                    $("#m-"+id).prepend('<p class = "shout_msg">' +result[i]+ '</p>');
                                }
                            }
                        });
                    })
                });

PHP代码

<?php

if(isset($_REQUEST['sender']) AND isset($_REQUEST['receiver']) ){

    $sender = $_REQUEST['sender'];
    $receiver = $_REQUEST['receiver'];

        require_once 'dc_chat.php';
        $mysqli = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME);

        $result = $mysqli -> query("SELECT id from users where username LIKE '{$sender}'");
        $row = mysqli_fetch_row($result); 
        $sender_id = $row[0]; 

        $result = $mysqli -> query("SELECT id from users where username LIKE '{$receiver}'");
        $row = mysqli_fetch_row($result); 
        $receiver_id = $row[0]; 


        $sql = $mysqli -> query("SELECT username from users where id in (select sender_id from messagse where sender_id = $sender_id )");

        $row = mysqli_fetch_row($sql); 
        $name = $row[0];    


        //$sql = $mysqli -> query("SELECT * from messagse where (sender_id = $sender_id AND receiver_id = $receiver_id) OR (sender_id = $receiver_id AND receiver_id = $sender_id) ");  

        $sql = $mysqli -> query("SELECT * FROM `messagse` WHERE (sender_id = $sender_id AND receiver_id = $receiver_id) OR (sender_id = $receiver_id AND receiver_id = $sender_id) order by id desc LIMIT 5");  

            $arr = array();
              while($row = mysqli_fetch_array($sql)) {
                                $arr[] = $name." ". $row[3]." ".$row[4];
                            }
                echo json_encode($arr);
        }
    ?>

Answer 1

但由于有多个用户，我需要存储不同的ID。我应该怎么做。

您应该按照要检索过去消息的用户的ID排序，而不是按表的ID排序。这样你可以将它限制在你想要的数字，例如限制5.然后你可以限制5,5等。

加载较早的会话消息

1 个答案: