留言板------Ajax与mysql数据交互02

接01部分，jq的ajax请求：

这部分是php代码部分：

注意：这部分我写成了公共代码，因为我在学习做其他东西时调用了，所以下面的代码会有

include_once "comment.php";

这一行是引用其他代码

0){
				$arr = ["error"=>0,"id"=>$insertId,"time"=>$times];
				echo json_encode($arr);//将数组转化为json，方便前端使用
			}
			else{
				$arr = ["error"=>1,"msg"=>"留言失败，请重试!"];
				echo json_encode($arr);//将数组转化为json，方便前端使用
			}
	 		break;
			
		case 'up':
			$id = $_GET['id'];
			$search = "SELECT up FROM microblog WHERE id = $id";
			$result = mysqli_query($link, $search);
			$upNum = mysqli_fetch_row($result)[0];
			$upNum++;
			$query = "UPDATE microblog SET up='{$upNum}' WHERE id = '{$id}'";
			mysqli_query($link,$query);
			if(mysqli_affected_rows($link)){//更新数据成功
				echo '{"error":"0"}';
			}
			else{//更新失败
				echo '{"error":"1","msg":"点赞失败！"}';
			}
			break;
			
		case 'down':
			$id = $_GET['id'];
			$search = "SELECT down FROM microblog WHERE id = $id";
			$result = mysqli_query($link, $search);
			$downNum = mysqli_fetch_row($result)[0];
			$downNum++;
			$query = "UPDATE microblog SET down='{$downNum}' WHERE id = '{$id}'";
			mysqli_query($link,$query);
			if(mysqli_affected_rows($link)){//更新数据成功
				echo '{"error":"0"}';
			}
			else{//更新失败
				echo '{"error":"1","msg":"踩失败！"}';
			}
			break;	
		case 'remove':
			$id = $_GET['id'];
			$query ="DELETE FROM microblog WHERE id='{$id}'";
			mysqli_query($link,$query);
			if(mysqli_affected_rows($link)>0){//删除数据成功
				echo '{"error":"0"}';
			}
			else{
				echo '{"error":"1","msg":"删除失败！"}';
			}
			break;
		case 'count'://返回总页码
			$query = "SELECT count(id) FROM 	microblog";
			$result = mysqli_query($link, $query);
			$count = mysqli_fetch_row($result)[0];//以索引数组形式返回查询结果
			$countPage = ceil($count/5);
			echo '{"error":"0","countPage":"'.$countPage.'"}';
			break;	
		case 'page'://点击分页或者是页面第一次加载
			$index = $_GET["num"]*5;
			$search = "SELECT * FROM microblog ORDER BY id DESC LIMIT {$index},5";//倒叙查询留言
			$result = mysqli_query($link, $search);
			$arr = [];//存查询出来的数据
			while($row = mysqli_fetch_assoc($result)){
				array_unshift($arr,$row);
			}
//			print_r($arr);
//			{"error":"0","info":[{},{},{},{},{}]}
			$resultArr = ["error"=>"0","info"=>$arr];
			echo json_encode($resultArr);
			break;
		
	 }
?>