SQLSTATE[HY000]: General error: 1364 Field 'category_id' doesn't have a default value

I think it has something to do with the fillable in your Product model.

Try to add this in your Product.php:

protected $fillable = [
    'category_id'
]

You don't inform about the category_id when you fill your model.

 if ($request->isMethod('post'))
    {
    $data = $request->all();

    $product = new Product;
    $product->product_name = $data['product_name'];
    $product->product_code = $data['product_code'];
    $product->product_color = $data['product_color'];
    $product->category_id = $data['category_id']; // <<< NEW LINE

You should maybe take a look at validation : https://laravel.com/docs/5.7/validation

And you can set a method for GET method, and another one for POST method in your route file, and thus don't need to check if ($request->isMethod('post')) at the top of your controller.

@EQUALIZEE - sory still same error

@developer_ You're not providing a category_id. You're missing $product->category_id = $data['category_id']; in your controller

@VILFAGO - sory still same errror

@SIGNAR - i have added this but nthing happened

@developer_ Have you made sure that $data['category_id'] gets passed through to your controller? Does your $categories_drop_down output the options with a value correctly? At least try dd($data['category_id']);. If that's empty, then check the HTML

@SIGNAR - yes $data['category_id'] gets passed through controller, and $categories_drop_down is only showing the category id in output not the text formatted value like other values

@developer_ what does dd($data['category_id']); show?

@signar a screenshot of error https://imageshack.com/i/pnWM7Rmnp

   public function addProduct(Request $request)
   {
    if ($request->isMethod('post'))
    {
    $data = $request->all();

    $product = new Product;
    $product->product_name = $data['product_name'];
    $product->product_code = $data['product_code'];
    $product->product_color = $data['product_color'];
    $product->category_id = $data['category_id']; // <<< NEW LINE
    if ( ! empty($data['description']))
    {
        $product->description = $data['description'];
    }
    else
    {
        $product->description = '';
    }
    $product->price = $data['price'];

    // Upload Image
    if ($request->hasFile('image'))
    {
        $image_tmp = Input::file('image');
        if ($image_tmp->isValid())
        {
            $extension = $image_tmp->getClientOriginalExtension();
            $filename = rand(111, 99999) . '.' . $extension;
            $large_image_path = 'images/backend_images/products/large/' . $filename;
            $medium_image_path = 'images/backend_images/products/medium/' . $filename;
            $small_image_path = 'images/backend_images/products/small/' . $filename;
            // Resize Images
            Image::make($image_tmp)->save($large_image_path);
            Image::make($image_tmp)->resize(600, 600)->save($medium_image_path);
            Image::make($image_tmp)->resize(300, 300)->save($small_image_path);
            // Store image name in products table
            $product->image = $filename;
        }
    }

    dd($request->all(), $product); // <<< NEW LINE
    $product->save();

//[...]

What did you get ?

@developer_ I see the error which is the same as the title of this thread. You're still not setting the category_id value for the product when creating a product. You need to fix that by $product->category_id = $data['category_id']

@SIGNAR - only id "9"

@developer_ Good! Then the category_id is passed through. You only need to set it on your product :) $product->category_id = $data['category_id'];

@VILFAGO - i get this https://imageshack.com/i/pmsfPCePp

@SIGNAR - bro i hv added this line and also clear the view using php artisan view:clear by i dont know y getting the same error

@developer_ The last image you sent to @vilfago means that the product was created correctly. Problem solved :)

@signar no, the dd was before saving to db... but everything seems clear and correct.

You can maybe check in the Product if you have the category_id attribute, and if yes... I don't understand the error you get...

Can we see your "Product" Model ?

@SIGNAR - but its not saving in db and m not getting the added product in browser, its still showing the same error, now i hv cleard the histroy of browser but still same issue

@vilfago You're right. And I don't understand the error eighter. There must be a spelling error or something like that..

product model :

  public function product(){
    return $this->hasMany('App\Product','product_id');
  }

@VILFAGO - public function product(){ return $this->hasMany('App\Product','product_id'); }

The App\Product file, not the method in probably your category model.

But with what you show, you can try

 public function addProduct(Request $request)
   {
    if ($request->isMethod('post'))
    {
    $data = $request->all();
    $category = \App\Category::findOrFail($data['category_id']); //<<< NEW LINE

    $product = new Product;
    $product->product_name = $data['product_name'];
    $product->product_code = $data['product_code'];
    $product->product_color = $data['product_color'];

    if ( ! empty($data['description']))
    {
        $product->description = $data['description'];
    }
    else
    {
        $product->description = '';
    }
    $product->price = $data['price'];

    // Upload Image
    if ($request->hasFile('image'))
    {
        $image_tmp = Input::file('image');
        if ($image_tmp->isValid())
        {
            $extension = $image_tmp->getClientOriginalExtension();
            $filename = rand(111, 99999) . '.' . $extension;
            $large_image_path = 'images/backend_images/products/large/' . $filename;
            $medium_image_path = 'images/backend_images/products/medium/' . $filename;
            $small_image_path = 'images/backend_images/products/small/' . $filename;
            // Resize Images
            Image::make($image_tmp)->save($large_image_path);
            Image::make($image_tmp)->resize(600, 600)->save($medium_image_path);
            Image::make($image_tmp)->resize(300, 300)->save($small_image_path);
            // Store image name in products table
            $product->image = $filename;
        }
    }

 // $product->save(); <<< comment this line
    $category->products()->save($product);

//[...]

It should at least give you a new error.

@VILFAGO - error:

 Call to undefined method App\Category::products()

is there any issue in model than can u tell me

oO

So please, put all code of both Product and Category Model.

@VILFAGO - category model:

 public function categories(){
    return $this->hasMany('App\Category','parent_id');
}

product model:

public function product(){
    return $this->hasMany('App\Product','product_id');
 }

You have to inverse both method.

Add product (and named it products) to Category, and category (instead of categories) to your product model.

And give us all the text please... it usually begins with

namespace App;

use Illuminate\Database\Eloquent\Model;

class Product extends Model
{
 [...]
}

@VILFAGO - changed category model:

<?php

   namespace App;

   use Illuminate\Database\Eloquent\Model;

   class Category extends Model
  {
    public function category(){
    return $this->hasMany('App\Category','parent_id');
  }
 }

product model:

   <?php

    namespace App;

    use Illuminate\Database\Eloquent\Model;

   class Product extends Model
   {
     public function products(){
      return $this->hasMany('App\Product','product_id');
    }
  }

<?php

   namespace App;

   use Illuminate\Database\Eloquent\Model;

   class Category extends Model
  {
     public function products(){
     return $this->hasMany('App\Product');
  }

}

   <?php

    namespace App;

    use Illuminate\Database\Eloquent\Model;

   class Product extends Model
   {
    public function category(){
    return $this->belongsTo('App\Category');

    }
  }

 public function addProduct(Request $request)
   {
    if ($request->isMethod('post'))
    {
    $data = $request->all();
    $category = \App\Category::findOrFail($data['category_id']); //<<< NEW LINE

    $product = new Product;
    $product->product_name = $data['product_name'];
    $product->product_code = $data['product_code'];
    $product->product_color = $data['product_color'];

    if ( ! empty($data['description']))
    {
        $product->description = $data['description'];
    }
    else
    {
        $product->description = '';
    }
    $product->price = $data['price'];

    // Upload Image
    if ($request->hasFile('image'))
    {
        $image_tmp = Input::file('image');
        if ($image_tmp->isValid())
        {
            $extension = $image_tmp->getClientOriginalExtension();
            $filename = rand(111, 99999) . '.' . $extension;
            $large_image_path = 'images/backend_images/products/large/' . $filename;
            $medium_image_path = 'images/backend_images/products/medium/' . $filename;
            $small_image_path = 'images/backend_images/products/small/' . $filename;
            // Resize Images
            Image::make($image_tmp)->save($large_image_path);
            Image::make($image_tmp)->resize(600, 600)->save($medium_image_path);
            Image::make($image_tmp)->resize(300, 300)->save($small_image_path);
            // Store image name in products table
            $product->image = $filename;
        }
    }

 // $product->save(); <<< comment this line
    $category->products()->save($product);

//[...]

@VILFAGO - SQLSTATE[HY000]: General error: 1364 Field 'care' doesn't have a default value