php gettype fix

Following function I created is to store data in a database with the correct type.

I have several questions:

1. It makes sense to me to turn empty strings in to NULL. Are there consequences I am not considering?
2. What is a good max_length value for sqlite3 text. I know blob and text length constrains are the same, but are there any other considerations like displaying the data in a shell, etc.
3. Is there a simple way to check if data is an image, and what type, since mime is not available at this stage?

4. Does something stick out that I am missing?

   public static function getType($value, $max_length = 50){
   
       $type = gettype($value);
   
       if($type == 'NULL'
               || $type == 'boolean'
           开发者_StackOverflow    || $type == 'integer'
               || $type == 'double'
               || $type == 'object'
               || $type == 'resource'
               || $type == 'array'
           )
           return array('type'=>$type,'value'=>$value);
   
       if($type == 'string' && empty($value))
           return array('type'=>'NULL','value'=>$value);
   
       if($type == 'string' && strlen($value) > $max_length)
           return array('type'=>'blob','value'=>$value);
   
       if($type == 'string' && substr($value, 0,1) === '0')
           return array('type'=>'string','value'=>$value);
   
       if($type == 'string' && is_numeric($value)){
           $int   = (int) $value;
           $float = (float) $value;
   
           if($int == $value){
               $value = $int;
               $type = 'integer';
           }elseif($float == $value){
               $value = $float;
               $type = 'double';
           }
       }elseif($type == 'string'){
           return array('type'=>$type,'value'=>$value);
       }else{
           $type = 'blob';
       }
       return array('type'=>$type,'value'=>$value);
   }