How to check the values ​​of all filenames for uniqueness?

Question

Laravel

there is an array:

array:5 [
  0 => array:4 [
    "preview" => "blob:http://127.0.0.1:8000/d8d6b9e3-97e2-46c7-a2e9-8f05f9f59b63"
    "uploaded" => 1
    "filename" => "5ba4d101048ed_887ef694391f92971f6358c671c55e27.jpg?1537528066083"
    "isCover" => 1
  ]
  1 => array:3 [
    "preview" => "blob:http://127.0.0.1:8000/c83d8037-a0da-412e-b7ea-4872e7d33237"
    "uploaded" => 1
    "filename" => "5ba4d10228059_857336b00f3eefefdfefa3339416ebf9.jpg?1537528067092"
  ]
  2 => array:3 [
    "preview" => "blob:http://127.0.0.1:8000/2c1ccb68-a578-4f88-8d57-30a1072b5d5b"
    "uploaded" => 1
    "filename" => "5ba4d10321b3a_33197f8397faa75bb157b9e784f2f128.jpg?1537528068000"
  ]
  3 => array:3 [
    "preview" => "blob:http://127.0.0.1:8000/4b946662-90a6-4b28-94e0-e4c47627c35e"
    "uploaded" => 1
    "filename" => "5ba4d104d419a_74310cd34625bf5dc189f3adcfd7f61a.jpg?1537528069764"
  ]
  4 => array:3 [
    "preview" => "blob:http://127.0.0.1:8000/6457157d-bfb2-4ee9-a3ed-333e9c900bb1"
    "uploaded" => 1
    "filename" => "5ba4d10409a0e_becb3d4e554cef42eb5d8261f392d288.jpg?1537528068828"
  ]
]

I need to use the Laravel Validator to check each filename field for uniqueness in the pictures (id, name) table and for the existence of a file in the system, how can I do this while using a minimum of code?
PS: There was an idea to collect the names first, then do a whereIn in the database, then collect only the unique names and then check them for their presence in the file system, maybe someone has better solutions to the problem.

Answer 1

Have you tried the rule ? 'fields.*.filename' => 'unique'

Answer 2

'array.*.filename' => 'unique:table,column'
Checks for uniqueness against the column field of the table table in the database.
But with the presence of a standard method in the file system, you need to write your own