如何在mysql php中保存json数组

Question

我正在尝试将 json 数组保存在 mysql 中，但出现错误。首先，我试图将其保存为字符串 使用内爆函数。但是在获取数据时没有得到相同的字符串。现在尝试按原样保存 json 字符串。这样我就可以轻松获取它。这是 json 字符串

{"us_id":"1","stu_id":"6","class_id":"3","req_x":[
  { "u_id":"1", "u_details":"testing user", "charges":"12.50"},
  { "u_id":"2", "u_details":"testing user 2", "charges":"10.50" },
  { "u_id":"3", "u_details":"testing user 3", "charges":"9.50" }
]}

我需要将 req_x 字段保存在 db 的 diff 列中

$req_x = '[
  { "u_id":"1", "u_details":"testing user", "charges":"12.50"},
  { "u_id":"2", "u_details":"testing user 2", "charges":"10.50" },
  { "u_id":"3", "u_details":"testing user 3", "charges":"9.50" }
]';

这是使用 implode 保存 json 字符串的代码

$req_dets= implode("&",array_map(function($a) {return implode("|",$a);},$req_x));

现在我试图简单地保存它

json_decode($req_x)

但它不起作用。返回错误 json_decode() 期望参数 1 是给定的字符串数组

Answer 1

如果你从这个 JSONstring 开始

$start = 
'{   "us_id":"1",
    "stu_id":"6",
    "class_id":"3",
    "req_x":[
                { "u_id":"1", "u_details":"testing user", "charges":"12.50"},
                { "u_id":"2", "u_details":"testing user 2", "charges":"10.50" },
                { "u_id":"3", "u_details":"testing user 3", "charges":"9.50" }
            ]
}';

而您只想将req_x 数组保存到数据库中......

$obj = json_decode($start);
$arr = $obj->req_x;
// make a json string of that
$json_req_x = json_encode($arr);

echo $json_req_x;

RESULT 是一个 JSONString

[
    {"u_id":"1","u_details":"testing user","charges":"12.50"},
    {"u_id":"2","u_details":"testing user 2","charges":"10.50"},
    {"u_id":"3","u_details":"testing user 3","charges":"9.50"}
]

现在您可以像处理任何其他列一样使用 INSERT 或 UPDATE 将字符串 $json_req_x 放入数据库中。

Answer 2

该列的数据类型是什么？要存储 JSON 数据，请尝试将列数据类型更改为 JSON。