database.php

<?php
class database{
 private $host;
 private $dbusername;
 private $dbpassword;
 private $dbname;


 protected function connect(){
      $this->host='localhost';
      $this->dbusername='root';
      $this->dbpassword='';
      $this->dbname='crud';
      $con=new mysqli($this->host,$this->dbusername,$this->dbpassword,$this->dbname);
       return $con;
 }
}

class query extends database{
    public function getData ($table, $field='*', $condition_arr='', $order_by_field='', $order_by_type='desc', $limit=''){
        $sql="select $field from $table ";
        if($condition_arr!=''){
            $sql.=' where ';
            $c=count($condition_arr);
            $i=1;
           foreach($condition_arr as $key=>$val){
            if($i==$c){
                $sql.="$key='$val'";
            }
            else{
                $sql.="$key='$val' and ";
            }
            $i++;
           }
           
        }

        if($order_by_field!=''){
            $sql.=" order by $order_by_field $order_by_type ";
        }

     

        if($limit!=''){
            $sql.=" limit $limit ";
        }
       
        $result=$this->connect()->query($sql);
        if($result->num_rows>0){
            $arr=array();
            while($row=$result->fetch_assoc()){
                $arr[]=$row;
            }
            return $arr;
        } else{
            return 0;
        }
    }

    public function insertData ($table, $condition_arr){
        
        if($condition_arr!=''){
           foreach($condition_arr as $key=>$val){
           $fieldArr[]=$key;
           $valueArr[]=$val;
            
           }
           $field=implode(",",$fieldArr);
           $value=implode("','",$valueArr);
           $value="'".$value."'";
           $sql="insert into $table($field) values($value) ";              
           $result=$this->connect()->query($sql);   
        }

           
    }

    public function deleteData ($table, $condition_arr){
        
        if($condition_arr!=''){
            $sql="delete from $table where ";     
            $c=count($condition_arr);
            $i=1;
           foreach($condition_arr as $key=>$val){
            if($i==$c){
                $sql.="$key='$val'";
            }
            else{
                $sql.="$key='$val' and ";
            }
            $i++;
           }    
           $result=$this->connect()->query($sql);   
        }
     
    }

    public function updateData ($table, $condition_arr, $where_field, $where_value){
        
        if($condition_arr!=''){
            $sql="update $table set ";     
            $c=count($condition_arr);
            $i=1;
           foreach($condition_arr as $key=>$val){
            if($i==$c){
                $sql.="$key='$val'";
            }
            else{
                $sql.="$key='$val', ";
            }
            $i++;
           }   
            $sql.=" where $where_field='$where_value' "; 
           $result=$this->connect()->query($sql);   
        }
     
    }

    public function get_safe_str($str){
        if($str!=''){
           return mysqli_real_escape_string($this->connect(),$str);
    }
}
}

?>