分析一下这个json {"name":"12312","project_id":"87156","project_name":"上上下下左左右右baba与聚法科技（长春）有限公司与公司、证券、保险、票据等有关的民事纠纷","client":"[{"type":"自然人","customer_id":"80236","customer_name":"上上下下左左右右baba"}]","sign_date":"2023-06-06","expire_date":"2023-06-21","subject_amount":"123","contract_amount":"123","charge_method":"一次性,分阶段,风险,计时","equity_amount":"13811","amount_info":"[{"type":"一次性","pay_date":"2023-07-03","charge_amount":"12"},{"type":"分阶段","pay_date":"2023-06-13","charge_amount":"123","is_satisfy":"是","pay_condition":"12312"},{"type":"风险","pay_date":"","charge_amount":"","is_satisfy":"是","pay_condition":"123","basic_amount":"123","risk_amount":"12","object_amount":"123123","object":"赔偿金","risk_prop":"13213","member":"","rate":"","hours":""},{"type":"计时","member_id":"392159","member":"曹野","rate":"11","hours":"1231"}]","seal_person":"123","seal_type":"律所公章,法人名章,财务章","seal_num":"123","file_path":"[{"title":"导入错误数据 (15).xls","path":"382585/1686381522542/导入错误数据 (15).xls","size":"91136"},{"title":"3.txt","path":"382585/1686561731102/3.txt","size":44078}]","remark":"123123"} 并使用php转换成字符串

这是一个包含多个键值对的 JSON 对象。其中包括合同的一些基本信息，如名称、项目 ID、签订日期、到期日期、合同金额、收费方式、盖章人、盖章类型、盖章数量、文件路径和备注等。其中一些键的值是 JSON 数组，需要进一步解析。

以下是将该 JSON 对象转换成字符串的 PHP 代码：

$json = '{"name":"12312","project_id":"87156","project_name":"上上下下左左右右baba与聚法科技（长春）有限公司与公司、证券、保险、票据等有关的民事纠纷","client":"[{"type":"自然人","customer_id":"80236","customer_name":"上上下下左左右右baba"}]","sign_date":"2023-06-06","expire_date":"2023-06-21","subject_amount":"123","contract_amount":"123","charge_method":"一次性,分阶段,风险,计时","equity_amount":"13811","amount_info":"[{"type":"一次性","pay_date":"2023-07-03","charge_amount":"12"},{"type":"分阶段","pay_date":"2023-06-13","charge_amount":"123","is_satisfy":"是","pay_condition":"12312"},{"type":"风险","pay_date":"","charge_amount":"","is_satisfy":"是","pay_condition":"123","basic_amount":"123","risk_amount":"12","object_amount":"123123","object":"赔偿金","risk_prop":"13213","member":"","rate":"","hours":""},{"type":"计时","member_id":"392159","member":"曹野","rate":"11","hours":"1231"}]","seal_person":"123","seal_type":"律所公章,法人名章,财务章","seal_num":"123","file_path":"[{"title":"导入错误数据 (15).xls","path":"382585/1686381522542/导入错误数据 (15).xls","size":"91136"},{"title":"3.txt","path":"382585/1686561731102/3.txt","size":44078}]","remark":"123123"}';

$data = json_decode(str_replace('"', '"', $json), true);
$str = '';

foreach ($data as $key => $value) {
    if (is_array($value)) {
        $value = json_encode($value);
    }
    $str .= $key . ':' . $value . ',';
}

$str = '{' . rtrim($str, ',') . '}';

echo $str;