public function stat(string $table, string $column, array $where = [], array $order = []): ?array{
    if ( $this->check() ){
      return $this->rselect_all([
        'tables' => [$table],
        'fields' => [
          $column,
          'num' => 'COUNT(*)'
        ],
        'where' => $where,
        'order' => $order,
        'group_by' => [$column]
      ]);
    }
    return null;
  }
public function stat(string $table, string $column, array $where = [], array $order = []): ?array{
    if ( $this->check() ){
      return $this->rselect_all([
        'tables' => [$table],
        'fields' => [
          $column,
          'num' => 'COUNT(*)'
        ],
        'where' => $where,
        'order' => $order,
        'group_by' => [$column]
      ]);
    }
    return null;
  }
public function stat ( string $ table , string $ column , array $ where = [ ] , array $ order = [ ] ) : ? array { if ( $ this -> check ( ) ) { return $ this -> rselect_all ( [ 'tables' => [ $ table ] , 'fields' => [ $ column , 'num' => 'COUNT(*)' ] , 'where' => $ where , 'order' => $ order , 'group_by' => [ $ column ] ] ) ; } return null ; }
Return an array with the count of values corresponding to the where conditions.

```php
\bbn\x::dump($db->stat('table_user', 'name', ['name' => '%n']));
/* (array)
[
[
"num" => 1,
"name" => "alan",
], [
"num" => 1,
"name" => "karen",
],
]
```

@param string|array $table The table's name or a configuration array.
@param string $column The field's name.
@param array $where The "where" condition.
@param array $order The "order" condition.
@return array
Return an array with the count of values corresponding to the where conditions .