Insert a random int that does not exist in Dtabase not working?-CodePudding

mt_rand() and random_int() both are generate only one numbe and insert it in database where the number is already exist. I want to clear that , I want to insert a random number that is not exist in database.

I took this code from here

In my case in laravel 8, the code looks like below

public function generateProductCode() {
    $number = mt_rand(1000000000, 9999999999); 

    // call the same function if the barcode exists in Dtabase already
    if ($this->productCodeExists($number)) {
        return $this->generateProductCode();
    }

    // otherwise, it's valid and can be used
    return $number;
}

public function productCodeExists($number) {
    // query the database and return a boolean
    // for instance, it might look like this in Laravel
    return Product::where('product_code', $number)->exists();
}

The model name is Product and DB table name is products. 'product_code' is the column where I want to do this query. In store function where I Call generateProductCode() function, it looks like below

public function store(Request $request)
{
    $product = new Product;
    //Generate a Product key
    $product->product_code = $this->generateProductCode();
    $product->save();
 }

It returns all time only one numbers that is 2147483647 . Photo is here What is the wrong? What is the perfect query to check exist so that it returns another that is not exist in the database.

CodePudding user response：

according to php doc:

mt_rand: This function does not generate cryptographically secure values, and should not be used for cryptographic purposes

you can use random_int

it Generates cryptographic random integers that are suitable for use where unbiased results are critical

 $number = random_int(1000000000, 9999999999);

CodePudding user response：

You should create a recursion function check if the number is already used or not.

public function store(Request $request)
{
    $product = new Product;
    //Generate a Product key
    $product->product_code = $this->newRandomInt();
    $product->save();
 }

 private function newRandomInt()
    {
        $number = random_int(1000000000, 9999999999); 
        $isUsed =  Product::where('number', $number)->first();
        if ($isUsed) {
            return $this->newRandomInt();
        }
        return $number;
    }