Notice: undefined index: db in C:\mylinks\kripto\crypto\test.php on line 2

Notice: Undefined index: db in C:\Mylinks\Kripto\Crypto\test.php on line 2

<pre><?php
  if($_POST['db'] == 'LifeCoinWatchDB')
	{
		$sql = mysqli_query($pdo,"SELECT * FROM api_currency ");

        $row = mysqli_fetch_array($pdo);
		
		$LIVECOINWATCH_API = $row['LIVECOINWATCH_API'];
		 
		$data = json_encode(array('currency' => 'USD', 'sort' => 'rank', 'order' => 'ascending', 'offset' => 0, 'meta' => false));

		$headers = array(
		"content-type: application/json",
		"x-api-key: LIVECOINWATCH_API",
		);

		$qs = http_build_query($data); // query string encode the parameters
 
		$url = "https://api.livecoinwatch.com/coins/list";
 
		$request = "{$url}?{$qs}"; // create the request URL
		
        echo $curl;
        
		$curl = curl_init(); // Get Curl resource
 
		curl_setopt_array($curl, array(
        CURLOPT_URL => $request,            // set the request URL
        CURLOPT_HTTPHEADER => $headers,     // set the headers 
        CURLOPT_RETURNTRANSFER => 1         // ask for raw response instead of bool
        )); 

       $response = curl_exec($curl); // Send the request, save the response

       curl_close($curl); // Close request     

        $decoded_json_lifecoinwatch = json_decode($response, true);// in index.php
		
		foreach($decoded_json_livecoinwatch['data'] as $livecoinwatch)// in index.html
		{

           $LIFECOINWATCH_code = $livecoinwatch['CODE'];
            $LIFECOINWATCH_name = $livecoinwatch['NAME'];
          
            $LIFECOINWATCH_name = htmlentities($LIFECOINWATCH_name, ENT_QUOTES, "UTF-8");		
			$checkSql = mysqli_query($pdo,"SELECT * FROM lcw_munt_lys WHERE CODE = '$LIFECOINWATCH_code' ") or die(mysqli_error($pdo));
            $checkSqlCount = mysqli_num_rows($checkSql);

            if($checkSqlCount > 0){
              
            }
            else{

				$insertSql = mysqli_query($pdo,"INSERT INTO lcw_munt_lys (CODE, NAME) VALUES('$LIFECOINWATCH_code', '$LIFECOINWATCH_name')") or die(mysqli_error($pdo));
			}
		}
	}
?>

if  isset(($_POST['db'] == 'LifeCoinWatchDB'))

Parse error: syntax error, unexpected 'isset' (T_ISSET), expecting '(' in C:\Mylinks\Kripto\Crypto\test.php on line 2