api.php

<?php
// read sensor ID ('esp8266-'+ChipID)
$headers = array();
if (isset($_SERVER['HTTP_SENSOR']))
    $headers['Sensor'] = $_SERVER['HTTP_SENSOR'];
if (isset($_SERVER['HTTP_X_SENSOR']))
    $headers['Sensor'] = $_SERVER['HTTP_X_SENSOR'];
// stop if no sensor name is detected
if (! isset($headers['Sensor'])) {
    die("no sensor id sended!");
}

// set the database parameters
$database_name = "luftdaten";
$database_host = "127.0.0.1";
$database_user = "change_it";
$database_password = "change_it";
$table_name = "sensor_data";

// establish the database connection
$pdo = new PDO('mysql:host=' . $database_host . ';dbname=' . $database_name, $database_user, $database_password);

// read the content sended to the API file
$json = file_get_contents('php://input');

// decode the encoded data into the results array
$results = json_decode($json, true);

// declare possible field names
$possible_fields = array(
    "durP1",
    "ratioP1",
    "P1",
    "durP2",
    "ratioP2",
    "P2",
    "SDS_P1",
    "SDS_P2",
    "temperature",
    "humidity",
    "BMP280_temperature",
    "BMP280_pressure",
    "BME280_temperature",
    "BME280_humidity",
    "BME280_pressure",
    "samples",
    "min_micro",
    "max_micro",
    "signal"
);

// copy sensor data values to values array
foreach ($results["sensordatavalues"] as $sensordatavalues) {
    $values[$sensordatavalues["value_type"]] = $sensordatavalues["value"];
}

if(!isset($values["temperature"]) && isset($values["BME280_temperature"])){
	$values["temperature"] = $values["BME280_temperature"];
}
if(!isset($values["temperature"]) && isset($values["BMP280_temperature"])){
	$values["temperature"] = $values["BMP280_temperature"];
}

if(!isset($values["humidity"]) && isset($values["BME280_humidity"])){
	$values["humidity"] = $values["BME280_humidity"];
}
   
// set missing fields to ensure their presence
foreach ($possible_fields as $possible_field) {
    if (! isset($values[$possible_field])) {
        $values[$possible_field] = NULL;
    }
}
// prepare the database query
$insert = $pdo->prepare("REPLACE INTO `" . $database_name . "`.`" . $table_name . "`(`Time`,`SensorID`,`durP1`,`ratioP1`,`P1`,`durP2`,`ratioP2`,`P2`,`SDS_P1`,`SDS_P2`,`Temp`,`Humidity`,`BMP280_temperature`,`BMP280_pressure`,`BME280_temperature`,`BME280_humidity`,`BME280_pressure`,`Samples`,`Min_cycle`,`Max_cycle`,`Signal`) VALUES (NOW(),:SensorID,:durP1,:ratioP1,:P1,:durP2,:ratioP2,:P2,:SDS_P1,:SDS_P2,:Temp,:Humidity,:BMP280_temperature,:BMP280_pressure,:BME280_temperature,:BME280_humidity,:BME280_pressure,:Samples,:Min_cycle,:Max_cycle,:Signal)");
// execute the database query
$insert->execute(array(
    ':SensorID' => $headers['Sensor'],
    ':durP1' => $values["durP1"],
    ':ratioP1' => $values["ratioP1"],
    ':P1' => $values["P1"],
    ':durP2' => $values["durP2"],
    ':ratioP2' => $values["ratioP2"],
    ':P2' => $values["P2"],
    ':SDS_P1' => $values["SDS_P1"],
    ':SDS_P2' => $values["SDS_P2"],
    ':Temp' => $values["temperature"],
    ':Humidity' => $values["humidity"],
    ':BMP280_temperature' => $values["BMP280_temperature"],
    ':BMP280_pressure' => $values["BMP280_pressure"],
    ':BME280_temperature' => $values["BME280_temperature"],
    ':BME280_humidity' => $values["BME280_humidity"],
    ':BME280_pressure' => $values["BME280_pressure"],
    ':Samples' => $values["samples"],
    ':Min_cycle' => $values["min_micro"],
    ':Max_cycle' => $values["max_micro"],
    ':Signal' => $values["signal"]
));