database_function.php

<?php
  function retype_check($a, $b){
    if ($a===null||$b===null) {
      statusCode(2);
    }
    if($a==$b){
      return false;
    }else{
      return true;
    }
  }
  function login_check($member_id, $member_pw){
    if ($member_id===null||$member_pw===null) {
      statusCode(2);
    }
    $member_id=Mysqli_real_escape_string(conn(), $member_id);
    $member_pw=Mysqli_real_escape_string(conn(), $member_pw);
    $login_query = "SELECT * FROM members WHERE member_id='$member_id'";
    $result = db($login_query);
    if($result->num_rows==1){
      global $row;
      $row=$result->fetch_array(MYSQLI_ASSOC);
      if($row['member_salt']==null){
        if($row['member_pw']==hash('sha3-256', $member_pw)){
          $_SESSION['member_reset']=$row['member_code'];
          statusCode(21);
        }
      }
      if($row['member_pw']==hash('sha3-256', $row['member_salt'].$member_pw)){
        return true;
      }
    }
    return false;
  }
  function overlap_check($table, $a, $b){
    if ($table==null||$a==null||$b==null) {
      statusCode(2);
    }
    $table=Mysqli_real_escape_string(conn(), $table);
    $a=Mysqli_real_escape_string(conn(), $a);
    $b=Mysqli_real_escape_string(conn(), $b);
    $overlap_query = "SELECT * FROM `$table` WHERE $a='$b'";
    $result = db($overlap_query);
    if($result->num_rows){
      return true;
    }
    return false;
  }
  function valid_check($table, $a, $b, $c, $d){
    if ($table==null||$a==null||$b==null||$c==null||$d==null) {
      statusCode(2);
    }
    $table=Mysqli_real_escape_string(conn(), $table);
    $a=Mysqli_real_escape_string(conn(), $a);
    $b=Mysqli_real_escape_string(conn(), $b);
    $c=Mysqli_real_escape_string(conn(), $c);
    $d=Mysqli_real_escape_string(conn(), $d);
    $valid_query = "SELECT * FROM `$table` WHERE `$a`='$b' AND `$c`='$d'";
    $result = db($valid_query);
    if($result->num_rows){
      return true;
    }
    return false;
  }
  function islogin(){
    if(isset($_SESSION['member_code'])){
      return true;
    }else{
      statusCode(19);
    }
  }
  function statusCode($status_code){
    $json = json_encode(array('status' => $status_code));
    echo $json;
    exit();
  }
?>