将字符串与字符串分开并存储在单独的行中

I'm trying to split my hashtags from a string from a single post so if there is more than one in a post they're separated into single #hashtags and put into separate rows in my hashtag table by their post_id.

Currently with my below function they're inserted into a single row and listed with a comma. How can I put them into an array and then store them individually, please?

Here is what I've tried to no avail:

      $hashtags ="#hashtag1 this is my string with two hashtags #hashtag2";
        if($hashtags==""){
                      }else{      
            function getHashtagsd($hashtags) {  
        $hashtagarray = FALSE;  
        preg_match_all("/(#\w+)/u", $hashtags, $matches);  
        if ($matches) {
            $hashtagarray = implode(",", $matches[0]);
        }
        return $hashtagarray;
    }

    $hashtagarray = getHashtagsd($hashtags);
$hashtagarray = getHashtagsd($hashtags);
$myArray1 = explode(';', $hashtagarray);
$myArray  = explode('#', $myArray1);

        $insertf = "INSERT INTO streamdata_hashtags(streamitem_hashtag_id,hashtag,streamitem_hashtag_timestamp) VALUES ($last_id,'$hashtagarray',NOW())";
                      $add_postf = mysqli_query($mysqli,$insertf) or die(mysqli_error($mysqli));

        }   

I added the explodes and got this error:

explode() expects parameter 2 to be string, array given in

You did a lot of coding that wasn't nessesary. I've updated the code and added some comments on how it works:

$hashtags = "#hashtag1 this is my string with two hashtags #hashtag2";

function getHashtagsd($hashtags) {
    preg_match_all("/(#\w+)/u", $hashtags, $matches);

    if ($matches) {
        return $matches[0]; // No need to implode, just return the array
    }
}

$hashtagarray = getHashtagsd($hashtags);

// Walk through the array and insert each hashtag
for($i = 0; $i < count($hashtagarray); $i++){
    $insertf = "INSERT INTO streamdata_hashtags(streamitem_hashtag_id,hashtag,streamitem_hashtag_timestamp) VALUES ($last_id,'". $hashtagarray[$i] ."',NOW())";
    $add_postf = mysqli_query($mysqli,$insertf) or die(mysqli_error($mysqli));
}