How to update a pivot table using Eloquent in laravel 5

Question

I am new to laravel. I am working on a laravel 5 app and I am stuck here. I have 2 models as such:

class Message extends Eloquent{

    public function user(         


        

Answer 1

Laravel 5.8

First, allow your pivot columns to be searchable by chaining the withPivot method to your belongsToMany

Copied from my own code to save time

// I have 3 columns in my Pivot table which I use in a many-to-many and one-to-many-through scenarios

$task = $user->goalobjectives()->where(['goal_objective_id'=>$goal_objective_id,'goal_obj_add_id'=>$goal_obj_add_id])->first(); //get the first record

$task->pivot->goal_objective_id = $new; //change your col to a new value

$task->pivot->save(); //save

The caveat is that your pivot table needs to have a primary 'id' key.

If you don't want that then you can try the following:

$tasks=$user->posts()->where(['posts_id'=>$posts_id,'expires'=>true])->get()->pluck('id'); // get a collection of your pivot table data tied to this user

$key=join(",",array_keys($tasks->toArray(),$valueYouWantToRemove));

$tasks->splice($key,1,$newValueYouWantToInsert);

$c = array_fill(0,$tasks->count(),['expires'=>true]); //make an array containing your pivot data

$newArray=$tasks->combine($c) //combine the 2 arrays as keys and values

$user->posts()->sync($newArray); //your pivot table now contains only the values you want

4th July Update Update to above snippet.

//Ideally, you should do a check see if this user is new
//and if he already has data saved in the junction table
//or are we working with a brand new user

$count = $user->goalobjectives->where('pivot.goal_obj_add_id',$request->record)->count();

//if true, we retrieve all the ids in the junction table 
//where the additional pivot column matches that which we want to update

if($count) {

$ids = $user->goalobjectives->where('pivot.goal_obj_add_id',$request->record)->pluck('id');

//convert to array

$exists = $ids->toArray();

//if user exists and both saved and input data are exactly the same
//there is no need
//to update and we redirect user back

if(array_sum($inputArray) == array_sum($exists)) {

//redirect user back

}

//else we update junction table with a private function
//called 'attachToUser'

$res = $this->attachToUser($user, $inputArray, $ids, $request->record);

}//end if

elseif(!$count) {

//we are working with a new user
//we build an array. The third pivot column must have equal rows as
//user input array

$fill = array_fill(0,count($inputArray),['goal_obj_add_id'=>$request->record]);

//combine third pivot column with user input

$new = array_combine($inputArray,$fill);

//junction table updated with 'user_id','goal_objective_id','goal_obj_add_id'

$res = $user->goalobjectives()->attach($new);

//redirect user if success

}

//our private function which takes care of updating the pivot table

private function attachToUser(User $user, $userData, $storedData, $record) {

//find the saved data which must not be deleted using intersect method

$intersect = $storedData->intersect($userData);

if($intersect->count()) {

//we reject any data from the user input that already exists in the database

$extra = collect($userData)->reject(function($value,$key)use($intersect){

return in_array($value,$intersect->toArray());

});

//merge the old and new data

$merge = $intersect->merge($extra);

//same as above we build a new input array

$recArray = array_fill(0,$merge->count(),['goal_obj_add_id'=>$record]);

//same as above, combine them and form a new array

$new = $merge->combine($recArray);

//our new array now contains old data that was originally saved
//so we must remove old data linked to this user
// and the pivot record to prevent duplicates

$storedArray = $storedData->toArray();

$user->goalobjectives()->wherePivot('goal_obj_add_id',$record)->detach($storedArray);

//this will save the new array without detaching
//other data previously saved by this user

$res = $user->goalobjectives()->wherePivot('goal_obj_add_id',$record)->syncWithoutDetaching($new);

}//end if

//we are not working with a new user
//but input array is totally different from saved data
//meaning its new data

elseif(!$intersect->count()) {

$recArray = array_fill(0,count($userData),['goal_obj_add_id'=>$record]);

$new = $storedData->combine($recArray);

$res = $user->goalobjectives()->wherePivot('goal_obj_add_id',$record)->syncWithoutDetaching($new);

}

//none of the above we return false

return !!$res;

}//end attachToUser function

This will work for pivot table which doesn't have a primary auto increment id. without a auto increment id, user cannot update,insert,delete any row in the pivot table by accessing it directly.