从用户ID的数组中选择帖子ID - mysql

Question

I have an Array of id's I follow if I echo:

echo json_encode($followingIds);

prints:

[{"User_two_id":"3"},{"User_two_id":"4"},{"User_two_id":"5"}]

I now want to select All id's from Post table where the value/s of Author are equal to the value of my User_two_id's in my array.

"Author is indexing id's of user_two"

Here is where I've got so far which is not working

function getPosts( $follwingIds ) {

        $sql = "SELECT id
        FROM posts
        WHERE Author IN ('$follwingIds')
        GROUP BY id
        HAVING COUNT(DISTINCT Author)";

    $result = $this->conn->query( $sql );

    if ( $result != null ) {

        while ( $row = $result->fetch_assoc() ) {
            $returnArray[] = $row;
        }
    }




}

Answer 1

One issue is here:

WHERE Author IN ('$follwingIds')

here $follwingIds in an JSON object where as mysql IN required value in comma separated values. So instead of making an json array convert it to string like:

$follwIds = implode(',', array_column($follwingIds, 'User_two_id'));

and use it in query like:

WHERE Author IN ($follwIds)