if add composite primary/unique key index, migration missing one foreign key index

[paul38467]

• Laravel Version: 7.28.3
• Homestead 10.0.0

Description:

if add composite primary/unique key index and with two foreign key index
in phpMyAdmin / HeidiSQL show missing one of the foreign key index

Steps To Reproduce:

pivot table migration:

public function up()
{
    Schema::create('car_region', function (Blueprint $table) {
        $table->unsignedBigInteger('car_id');
        $table->unsignedSmallInteger('region_id');
        $table->timestamps();

        $table->primary(['car_id', 'region_id']);
        $table->foreign('car_id')->references('id')->on('cars');
        $table->foreign('region_id')->references('id')->on('regions');
    });
}

The index showing in phpMyAdmin / HeidiSQL is:

Keyname                         Type    Unique  Packed  Column  
_________________________________________________________________
PRIMARY                         BTREE   Yes     No      car_id
                                                        region_id
-----------------------------------------------------------------
car_region_region_id_foreign    BTREE   No      No      region_id

The expected index should be:

Keyname                         Type    Unique  Packed  Column  
_________________________________________________________________
PRIMARY                         BTREE   Yes     No      car_id
                                                        region_id
-----------------------------------------------------------------
car_region_car_id_foreign       BTREE   No      No      car_id
-----------------------------------------------------------------
car_region_region_id_foreign    BTREE   No      No      region_id

If remove the composite primary/unique key index, it show the correct both index:

        //$table->primary(['car_id', 'region_id']);
        $table->foreign('car_id')->references('id')->on('cars');
        $table->foreign('region_id')->references('id')->on('regions');

Keyname                         Type    Unique  Packed  Column  
_________________________________________________________________
car_region_car_id_foreign       BTREE   No      No      car_id
-----------------------------------------------------------------
car_region_region_id_foreign    BTREE   No      No      region_id

[paulocuambe]

I think this is not supported check this comment in a related issue.

[parallels999]

https://github.com/topclaudy/compoships