[Calisthenics]

Code:

cache_get_field_content_int(0, registered, mysql);

pawn Code:

native cache_get_field_content_int(row, const field_name[], connectionHandle = 1);

It expects a column name to search for but `registered` is empty. The correct way would be:

pawn Code:

new Cache:aresult = mysql_query(mysql, "SELECT COUNT(*) AS total_accounts FROM `accounts`"),
    registered = cache_get_field_content_int(0, "total_accounts", mysql);

or

pawn Code:

new Cache:aresult = mysql_query(mysql, "SELECT COUNT(*) FROM `accounts`"),
    registered = cache_get_row_int(0, 0, mysql);

But you do not need a SELECT query at all. When you execute an INSERT query with auto increment, you retrieve the number generated (account ID) with `cache_insert_id`. This is how many players have registered (including deleted accounts).