如何將json轉換為php數組，只從json中提取特定值

Question

如何將JSON / PHP數組插入MYSQL

這是JSON值：

{"siteCurrentPowerFlow":
   {
        "updateRefreshRate":3,
        "unit":"kW",
        "connections": 
          [
            {"from":"PV","to":"Load"},
            {"from":"GRID","to":"Load"}
          ],
        "GRID":{"status":"Active","currentPower":65.63},
        "LOAD":{"status":"Active","currentPower":82.37},
        "PV":{"status":"Active","currentPower":16.74}
   }
}

這是我得到的PHP數組：

Array ( [siteCurrentPowerFlow] => Array ( [updateRefreshRate] => 3 [unit] => kW [connections] => Array ( [0] => Array ( [from] => PV [to] => Load ) [1] => Array ( [from] => GRID [to] => Load ) ) [GRID] => Array ( [status] => Active [currentPower] => 51.68 ) [LOAD] => Array ( [status] => Active [currentPower] => 79.43 ) [PV] => Array ( [status] => Active [currentPower] => 27.75 ) ) )

如何從PHP插入到mysql ？

我假設我需要使用foreach循環，但我不知道如何格式化foreach循環

$arrContextOptions = [
 'ssl' => [
   'verify_peer' => false,
   'verify_peer_name' => false
 ]
];
$data = file_get_contents($url, false, stream_context_create($arrContextOptions));
$decoded_data = json_decode($data, true);

print_r($decoded_data);

Answer 1

解碼你的json字符串

$data = (array) json_decode('put your json data here');

Answer 2

我需要插入“GRID”：{“status”：“Active”，“currentPower”：65.63} MYSQL：id，currentPower（mysql中的2列）| 當我這樣做：$ decoding_data = json_decode（$ urld，true）; $ data = $ decoding_data [“siteCurrentPowerFlow”] [“GRID”]; 的print_r（$數據）; 我得到了正確的數組：Array（[status] => Active [currentPower] => 65.63）如何只將這個插入到mysql

$decoded_data = json_decode($json_data,true);

$id = ... // set your id
$current_power = $decoded_data['siteCurrentPowerFlow']['GRID']['currentPower']; // fetch data from array

// connect to your db
$mysqli = new mysqli(...); // put your connection config here
if ($mysqli->connect_errno) {
    die("connection error: " . $mysqli->connect_error);
}

//Prepared statement
$sql = "INSERT INTO your_table (id, current_power) VALUES (?,?)"; // change columns to your table schema
$statement = $mysqli->prepare($sql);
$statement->bind_param('id', $id, $current_power); //type definition i for integer (id column) , d for double (current_power column). Bind your variables
$statement->execute();