#include <a_samp> first
#include <a_mysql> second

#define MYSQL_HOST    "localhost" //by default
#define MYSQL_USER    "root" //by default
#define MYSQL_PASSWORD "" // default user does not has password
#define MYSQL_DATABASE "test" // its allready set by default

new MySQL:g_SQL; //this is MySQL tag & variable to connect to your webserver mysql

public OnSomethingInit() // this is example
{
       new MySQLOpt:Option_Id = mysql_init_options(); // that depends what option you will set it
       mysql_set_option(Option_Id, SERVER_PORT, 3306); // lets say you set it for MySQL Default Port
       
       g_SQL = mysql_connect(.....); // Here goes your defines MYSQL_1, 2, 3, 4

       // than you check is your mysql open or closed by doing
       if(mysql_errno() != 0)
       {
              //print failed
       }
       else
       {
             //print success
       }

       // here you can create your table for your banned Ips depending on what you want to store
       return 1;
}

public OnSomeThingExit()
{
       mysql_close(g_SQL); // make sure you close your connection on gamemode exit or filterscript exit
       return 1;
}