INSERT INTO表打开DUPLICATE KEY UPDATE - 插入一个空行？

What is wrong with this MySQLi statment?

I want to do an INSERT INTO ON DUPLICATE KEY UPDATE

schema

'UID', 'char(17)', 'NO', 'PRI', NULL, ''
'stationID', 'int(11)', 'YES', '', NULL, ''
'temperature', 'float', 'YES', '', NULL, ''
'UV', 'float', 'YES', '', NULL, ''
'temperature_feels', 'float', 'YES', '', NULL, ''
'humidity', 'float', 'YES', '', NULL, ''
'weather_type', 'int(11)', 'YES', '', '-1', ''
'precipitation', 'float', 'YES', '', NULL, ''
'update_station_id', 'tinyint(4)', 'YES', '', '1', ''
'update_due', 'timestamp', 'YES', '', NULL, ''
'weather_status', 'varchar(128)', 'YES', '', NULL, ''

// code

    $sql = "INSERT INTO weather_data (uv, weather_status, weather_type, temperature, temperature_feels, humidity, precipitation, UID)
            VALUES (uv, weather_status, weather_type, temperature, temperature_feels, humidity, precipitation, UID)
            ON DUPLICATE KEY UPDATE uv = ?, weather_status = ?, weather_type = ?, temperature = ?, temperature_feels = ?, humidity = ?, precipitation = ?, UID = ?";
    $stmt = $dbh->prepare($sql);

    if (!$stmt) {
        throw new \Exception($dbh->error);
    }

    $stmt->bind_param('ssssssss', $uv, $weather_status, $weather_type, $temperature, $temperature_feels, $humidity, $precipitation, $UID);
    $stmt->execute();
    $stmt->close();

It seems to insert an empty row every time?

looks kind of crazy but the initial values for all the fields are strings ( of sorts ) and not placeholders. You would need to bind for each

$sql = "INSERT INTO weather_data (uv, weather_status, weather_type, temperature, temperature_feels, humidity, precipitation, UID)
        VALUES (?, ?, ?, ?, ?, ?, ?, ?)
        ON DUPLICATE KEY UPDATE uv = ?, weather_status = ?, weather_type = ?, temperature = ?, temperature_feels = ?, humidity = ?, precipitation = ?, UID = ?";

    $stmt->bind_param('ssssssssssssssss', $uv, $weather_status, $weather_type, $temperature,
                           $temperature_feels, $humidity, $precipitation, $UID, 
                           $uv, $weather_status, $weather_type, $temperature, 
                           $temperature_feels, $humidity, $precipitation, $UID);

Update your query to:

ON DUPLICATE KEY UPDATE 
  uv = VALUES(?),
  weather_status = VALUES(?),
  weather_type = VALUES(?),
  temperature = VALUES(?),
  temperature_feels = VALUES(?),
  humidity = VALUES(?),
  precipitation = VALUES(?),
  UID = VALUES(?)

Also the issue is that param go's with each ?, since after the insert you continue to use ? you need to add those arguments as well. You could avoid this with PDO using named params.

$stmt->bind_param('dsidddddidsidddddi', /* first set dsidddddi */ 
  $uv, 
  $weather_status,
  $weather_type,
  $temperature,
  $temperature_feels,
  $humidity,
  $precipitation,
  $UID,
  $uv, // because ? counts further.
  $weather_status,
  $weather_type,
  $temperature,
  $temperature_feels,
  $humidity,
  $precipitation,
  $UID,
);

$stmt->execute();