blocks|key|1157741|text|我打赌您正在检索非utf8编码的数据:尝试在SELECT查询之前放入mysql_query('SET+CHARACTER+SET+utf8')。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1157742|entityMap^0|M|6|Y|11|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

I bet you are retrieving data in non-utf8 encoding: try to put <code>mysql_query('SET CHARACTER SET utf8')</code> before your <code>SELECT</code> query.

blocks|key|1372940|text|如果您的PHP5.5或更高版本，您可以使用json_last_error_msg()，它将返回一个描述问题的字符串。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1372941|如果你没有5.5，但是在5.3以上，你可以使用json_last_error()来查看问题所在。|1372942|它将返回一个整数，您可以用它来识别function's+documentation中的问题。目前(2012.01.19)的标识为：|1372943|0+=+JSON_ERROR_NONE
1+=+JSON_ERROR_DEPTH
2+=+JSON_ERROR_STATE_MISMATCH
3+=+JSON_ERROR_CTRL_CHAR
4+=+JSON_ERROR_SYNTAX
5+=+JSON_ERROR_UTF8|code-block|syntax|javascript|1372944|这些可能会在将来的版本中更改，因此最好参考手册。|1372945|如果你低于5.3，你就不走运了，没有办法去问错误是什么。|1372946|entityMap|0|LINK|mutability|MUTABLE|url|http://php.net/manual/en/function.json-last-error-msg.php|1|http://php.net/manual/en/function.json-last-error.php|2^0|L|L|0|0|N|H|1|0|H|O|2|0|0|0|0^^$0|@$1|2|3|4|5|6|7|11|8|@]|9|@$A|12|B|13|1|14]]|C|$]]|$1|D|3|E|5|6|7|15|8|@]|9|@$A|16|B|17|1|18]]|C|$]]|$1|F|3|G|5|6|7|19|8|@]|9|@$A|1A|B|1B|1|1C]]|C|$]]|$1|H|3|I|5|J|7|1D|8|@]|9|@]|C|$K|L]]|$1|M|3|N|5|6|7|1E|8|@]|9|@]|C|$]]|$1|O|3|P|5|6|7|1F|8|@]|9|@]|C|$]]|$1|Q|3|-4|5|6|7|1G|8|@]|9|@]|C|$]]]|R|$S|$5|T|U|V|C|$W|X]]|Y|$5|T|U|V|C|$W|Z]]|10|$5|T|U|V|C|$W|Z]]]]

If you have at least PHP 5.5, you can use <a href="http://php.net/manual/en/function.json-last-error-msg.php" rel="noreferrer">json_last_error_msg()</a>, which will return a string describing the problem.

If you don't have 5.5, but are on/above 5.3, you can use <a href="http://php.net/manual/en/function.json-last-error.php" rel="noreferrer">json_last_error()</a> to see what the problem is.

It will return an integer, that you can use to identify the problem in the <a href="http://php.net/manual/en/function.json-last-error.php" rel="noreferrer">function's documentation</a>. Currently (2012.01.19), the identifiers are:

<pre><code>0 = JSON_ERROR_NONE
1 = JSON_ERROR_DEPTH
2 = JSON_ERROR_STATE_MISMATCH
3 = JSON_ERROR_CTRL_CHAR
4 = JSON_ERROR_SYNTAX
5 = JSON_ERROR_UTF8
</code></pre>

These can change in future versions, so it's better to consult the manual.

If you are below 5.3, you are out of luck, there is no way to ask what the error was.

blocks|key|1157862|text|我遇到了同样的问题，解决方案是使用我自己的函数而不是json_encode()|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1157863|echo+'["'+.+implode('","',+$row)+.+'"]';|code-block|syntax|javascript|1157864|entityMap^0|Q|D|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

I had the same problem and the solution was to use my own function instead of <code>json_encode()</code>

<pre><code>echo '["' . implode('","', $row) . '"]';
</code></pre>

blocks|key|1373044|text|您应该在json_encode中传递utf8编码的字符串。您可以像下面这样使用utf8_encode和array_map()函数：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1373045|<?php
++++$encoded_rows+=+array_map('utf8_encode',+$rows);
++++echo+json_encode($encoded_rows);
?>|code-block|syntax|javascript|1373046|entityMap^0|13|B|1F|B|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

You should pass utf8 encoded string in json_encode. You can use <code>utf8_encode</code> and <code>array_map()</code> function like below:

<pre><code>&lt;?php
 $encoded_rows = array_map('utf8_encode', $rows);
 echo json_encode($encoded_rows);
?&gt;
</code></pre>

blocks|key|1373112|text|ntd的anwser没有解决我的问题。对于那些处于同样情况的人，我最终是如何处理这个错误的:只需utf8_encode你的每个结果。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1373113|while($row+=+mysql_fetch_assoc($result)){
++++$rows[]+=+array_map('utf8_encode',+$row);
}|code-block|syntax|javascript|1373114|希望它能帮上忙！|1373115|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

ntd's anwser didn't solve my problem. For those in same situation, here is how I finally handled this error:
Just utf8_encode each of your results.

<pre><code>while($row = mysql_fetch_assoc($result)){
 $rows[] = array_map('utf8_encode', $row);
}
</code></pre>

Hope it helps!

blocks|key|1373163|text|现在，PHP.net推荐的设置字符集的方法如下：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1373164|mysqli_set_charset('utf8')|offset|length|1373165|entityMap|0|LINK|mutability|MUTABLE|url|http://php.net/manual/en/mysqli.set-charset.php^0|0|0|Q|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|O|8|@]|9|@$D|P|E|Q|1|R]]|A|$]]|$1|F|3|-4|5|6|7|S|8|@]|9|@]|A|$]]]|G|$H|$5|I|J|K|A|$L|M]]]]

The PHP.net recommended way of setting the charset is now this:

<a href="http://php.net/manual/en/mysqli.set-charset.php" rel="nofollow">mysqli_set_charset('utf8')</a>

blocks|key|1373262|text|对我来说，json_encode返回实体的null编码的问题是因为我的jsonSerialize实现获取了相关实体的整个对象；我通过确保获取相关/关联实体的ID并在有多个实体与要进行json序列化的对象相关联时调用->toArray()来解决这个问题。注意，我说的是实体上只有一个implements+JsonSerializable的情况。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1373263|entityMap^0|3W|R|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

For me, an issue where json_encode would return null encoding of an entity was because my jsonSerialize implementation fetched entire objects for related entities; I solved the issue by making sure that I fetched the ID of the related/associated entity and called ->toArray() when there were more than one entity associated with the object to be json serialized. Note, I'm speaking about cases where one <code>implements JsonSerializable</code> on entities.

For some reason the item "description" returns <code>NULL</code> with the following code:

<pre><code>&lt;?php
include('db.php');

$result = mysql_query('SELECT * FROM `staff` ORDER BY `id` DESC LIMIT 2') or die(mysql_error());
$rows = array();
while($row = mysql_fetch_assoc($result)){
 $rows[] = $row;
}

echo json_encode($rows);
?&gt;
</code></pre>

Here is the schema for my database:

<pre><code>CREATE TABLE `staff` (
 `id` int(11) NOT NULL AUTO_INCREMENT,
 `name` longtext COLLATE utf8_unicode_ci,
 `description` longtext COLLATE utf8_unicode_ci,
 `icon` longtext COLLATE utf8_unicode_ci,
 `date` longtext COLLATE utf8_unicode_ci,
 `company` longtext COLLATE utf8_unicode_ci,
 `companyurl` longtext COLLATE utf8_unicode_ci,
 `appurl` longtext COLLATE utf8_unicode_ci,
 PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci
</code></pre>

Here is what is echoed out on the page:

<pre><code>[{"id":"4","name":"Noter 2","description":null,"icon":"http:\/\/images.apple.com\/webapps\/productivity\/images\/noter2_20091223182720-thumb.jpg","date":"1262032317","company":"dBelement, LLC","companyurl":"http:\/\/dbelement.com\/","appurl":"http:\/\/noter2.dbelement.com"},{"id":"3","name":"Noter 2","description":null,"icon":"http:\/\/images.apple.com\/webapps\/productivity\/images\/noter2_20091223182720-thumb.jpg","date":"1262032317","company":"dBelement, LLC","companyurl":"http:\/\/dbelement.com\/","appurl":"http:\/\/noter2.dbelement.com"}]
</code></pre>

Any ideas?

json_encode is returning NULL?

数据库

由于某种原因，项目"description“返回NULL，代码如下：<?phpinclude('db.php');$result = mysql_query('SELECT * FROM `staff` ORDER BY `id` DESC LIMIT 2') or die(mysql_error());$rows =...

问json_encode是否返回NULL？
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