CODEWITHSUNDEEP
laraveleloquentsynchronization
Isuru Rodrigo
Isuru Rodrigo

Reputation: 85

Data duplicate when insert the data using laravel sync method?

I have used laravel sync mthod for belongsToMany relationship. After calling this method, sometimes duplicate data is inserted to the pivot table.

This the code I have used.

{

    $selectedScreenCategories = $this->screenCategorySiteFieldsModel->addSameKeyForElementsInArray($screenCategoryIds,'screen_category_id');
    $siteField->screenCategories()->sync($selectedScreenCategories);

}

This is the migration which is used to create pivot table.

{
    {
    public function up()
        {
            Schema::create('site_field_screen_categories',function (Blueprint $table){
                $table->increments('id');
                $table->unsignedInteger('screen_category_site_field_id')->nullable(false);
                $table->unsignedInteger('screen_category_id')->nullable(false);                
                $table->foreign('screen_category_site_field_id','screen_category_site_field_id')->references('id')->on('screen_category_site_fields');                            
                $table->foreign('screen_category_id')->references('id')->on('screen_categories');
            });
        }
    }
}

This is the belongsToMany relationship.

function screenCategories(){
    return  $this->belongsToMany('App\ScreenCategory','site_field_screen_categories','screen_category_site_field_id','screen_category_id');
}

This is the pivot table before calling the sync method.

enter image description here This is the sync array for $selectedScreenCategories.

[
    0 => ["screen_category_id" => 6]
    1 => ["screen_category_id" => 3]
    2 => ["screen_category_id" => 5]
]

This is the pivot table after calling sync method.

enter image description here

I spent several hours. Still could not able to find the solution.

Upvotes: 1

Views: 3514

Answers (2)

gihandilanka
gihandilanka

Reputation: 615

Solution.
Just change the integer keys in to string keys of the array $selectedScreenCategories which is passed in to sync function like below.

Change 

[
    0 => ["screen_category_id" => 6]
    1 => ["screen_category_id" => 3]
    2 => ["screen_category_id" => 5]
]

Into

[
    "Gfdsj" => ["screen_category_id" => 6]
    "pQrst" => ["screen_category_id" => 3]
    "uvWzy" => ["screen_category_id" => 5]
]

You can use str_random(5) php function to make random strings like "Gfdsj". This will fix your issue.

Reason for the issue.
Check the already existing record of the pivot table before run the sync function.
That record for screen_category_id = 1.

Then check the array $selectedScreenCategories which is passed to sync function. See the image below.

enter image description here

When we pass this array to sync function, because there is a record for screen_category_id = 1 already, above highlighted record is the reason to getting updated the already existing record as screen_category_id = 3. Now we have 2 records for screen_category_id = 3.
Hope you will understand.

Upvotes: 8

Mike Ross
Mike Ross

Reputation: 2972

If you want the combination to be unique in your pivot table, remove the id from pivot table. In order to stop duplicate record you need to make unique key. In your current table id is the primary key and incremental.

You can remove the id and create composite primary key like

$table->primary(['screen_category_site_field_id', 'screen_category_id']);

Above will really enforce unique data.

Alternative is you can keep the table as it is and detach the data first and sync again.

Upvotes: 1

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