在<>时过滤null
原生sql：
WHERE (`name` = 'aaa') AND WHERE ( `is_deleted` <> 1 OR `is_deleted` IS NULL )
thinkphp5.1链式调用
Db::table('table')->where($where)
->where(function ($query) {
$query->whereOr([
['is_deleted', '<>', 1]
])->whereOr('is_deleted', 'null');
})
->select();