Searching multiple terms with php - php

Question

I'm trying to get my search form to search for multiple terms.For example "Black dog".In my $keywords they are separated with commas (Black, dog).I know that i can just enter (Black dog, ) in my $keywords but I want them to be separated with commas.If I put single term (dog) it returns result for only that term.If I put 2 (Black dog) it returns 0 results.
<form class="form-inline pull-xs-right" action="search.php" method="POST" >
<input class="form-control" type="text" name="search" placeholder="Search">
<button class="btn btn-success-outline" name="searchh" type="submit" value=">>" >Search</button>
</form>
<?php
$i=null;
$search=null;
$result_query=null;
if(isset($_POST['search'])){
$get_value = addslashes($_POST['search']);
$search = mysqli_real_escape_string($con,"$get_value");
?>
<h2>Showing results for
<?php echo $_POST['search'] ?></h2>
<?php
if($search==''){
echo "<center><b>Please write something in the search box!</b></center>";
exit();
}
$search = $_POST['search'];
$terms = explode(" ", $search);
foreach ($terms as $each) {
$i++;
if ($i == 1)
$result_query .= "keywords LIKE '%$each%' ";
else
$result_query .= "OR keywords LIKE '%$each%' ";
}
$result_query = "SELECT * FROM content WHERE keywords LIKE '%".$search."%'";
$run_result = mysqli_query($con,$result_query);
// echo mysqli_num_rows($run_result);
// exit;
if(mysqli_num_rows($run_result)<1){
echo "<center>Sorry no matches found</center>";
exit();
}
while($row_result=mysqli_fetch_array($run_result))
{
$name=$row_result['name'];
$keywords=$row_result['keywords'];
$image=$row_result['image'];
$link=$row_result['link'];
?>