php - 服务 php 代码问题

Question

我已经在 php 中创建了服务，但我遇到了一些问题，这是我实现的代码

 <?php
include("db.php");
$month=10;
$year=date("Y");
$sq=mysql_query('select * from city where id=1 ORDER BY city ASC');
while($re1=mysql_fetch_array($sq)){
$id = $re1['id'];
$city = $re1['city'];
$city_id = $re1['id'];
echo '{ <br>"'.$city.'" : [ <br>'; 

$sql='select * from price where month="'.$month.'" and year="'.$year.'" and city="'.$id.'" ORDER BY day ASC';
$sql2=mysql_query($sql);
while($re2=mysql_fetch_array($sql2)){
echo  '{ <br>';
echo '"date" : "'.$re2["day"].'-'.$re2["month"].'-'.$re2["year"].'",<br>';

 if($re2['price']==''){ echo "Price : -- , <br>";}
else{
echo '"Price" : "'.$re2["price"].'" <br>';
}
echo '}, <br>';
}
echo ']<br>}';
}
?>

响应 json 格式如下。

{
"Ahmedabad" : [
{
"date" : "1-10-2014",
"Price" : "353"
},
{
"date" : "2-10-2014",
"Price" : "353"
},
{
"date" : "3-10-2014",
"Price" : "327"
},
]
}

但是在 json 格式结尾字典中如何删除这个 , 。你能建议我吗？

Answer 1

首先你不能拥有<br>在 JSON 响应中，除非该响应仅用于显示而不用于实际使用。

为了删除 ,最后，您需要在可以编辑的变量中创建每条“行”，而不仅仅是回显该行。

下面是一些可以实现这一点的代码:

<?php
include("db.php");
$month=10;
$year=date("Y");
$sq=mysql_query('select * from city where id=1 ORDER BY city ASC');
while($re1=mysql_fetch_array($sq)){
$id = $re1['id'];
$city = $re1['city'];
$city_id = $re1['id'];
echo '{
"'.$city.'" : [
'; 

$sql='select * from price where month="'.$month.'" and year="'.$year.'" and city="'.$id.'" ORDER BY day ASC';
$sql2=mysql_query($sql);
while($re2=mysql_fetch_array($sql2)){
    $line = '{
    ';

    $line.= '"date" : "'.$re2["day"].'-'.$re2["month"].'-'.$re2["year"].'",
    ';

    if($re2['price']=='')
    { 
        $line.= "Price : -- ,
        ";
    }
    else
    {
        $line.= '"Price" : "'.$re2["price"].'"
        ';
    }
    $line.= '},';
    echo $line;
}
$line = substr($line,0,-1);
echo ']
}';
}
?>

您应该使用内置 JSON 格式化函数的 PHP，例如 json_encode()

为了做出良好的 JSON 响应，您需要正确处理数据以避免格式错误。

所以这段代码更好地利用了 PHP 和 MySQL:

<?php
include("db.php");
$month=10;
$year=date("Y");
$sq=mysql_query('select * from city where id=1 ORDER BY city ASC');
while($re1=mysql_fetch_array($sq)){
    $id = $re1['id'];
    $city = $re1['city'];
    $city_id = $re1['id'];

    $sql='select * from price where month="'.$month.'" and year="'.$year.'" and city="'.$id.'" ORDER BY day ASC';
    $sql2=mysql_query($sql);
    while($re2=mysql_fetch_array($sql2)){
        // create each line in the city
        $line["date"] = $re2["day"].'-'.$re2["month"].'-'.$re2["year"];

        if($re2['price']=='')
        { 
            $line["Price"] = "--";
        }
        else
        {
            $line["Price"] = $re2["price"];
        }

        // add the line to the city
        $cities[$city][] = $line;
    }
}
// encode to json
json_encode($cities);
?>