If value exist in database don't save Laravel

Question

I'm creating a wishlist where the user can save his own products and save them. What I want is that a user can't save a product more than one time. So, what I'm doing is, if the product_id exists in the DB, I don't want to save the new record.

This is my code, what am I doing wrong?

public function addWishlist(Wishlist $wishlist) {        
    $wishlist->user_id = request('user_id');
    $wishlist->product_id = request('product_id');

    if(DB::table('wishlists')->where('product_id' !== $wishlist->product_id)) {
        $wishlist->save();
        return redirect()->back();
    }
}

Answer 1

what about this

public function addWishlist(Wishlist $wishlist) {  
    $userId = request('user_id');
    $productId = request('product_id');

    $found = Wishlist::where('user_id', $userId)->where('product_id', $productId)->count();

    if($found == 0) {
        $wishlist->user_id = $userId;
        $wishlist->product_id = $productId;
        $wishlist->save();
        return redirect()->back();
    }
}

Answer 2

public function addWishlist(Wishlist $wishlist) {   

    if(DB::table('wishlists')->where(['user_id'=>$user_id,'product_id'=>$wishlist->product_id])->exists()){
         // record already exist 
         return redirect()->back();
    }else{
         // record not exist , save the record
         $withlist = new Wishlist();     
         $wishlist->user_id = request('user_id');
         $wishlist->product_id = request('product_id');
         $wishlist->save();
         return redirect()->back();
    }
}

Answer 3

You can use firstOrNew and you need to check with user_id and product_id combination

    $wishlist::firstOrNew(array('user_id' => request('user_id'),'product_id'=>request('product_id')));
    $wishlist->user_id = request('user_id');
    $wishlist->product_id = request('product_id');
    $wishlist->save();
    return redirect()->back();

Answer 4

您是否尝试过FirstOrCreate（）

 $user = User::firstOrCreate(['email' => $email])