Laravel 8 Cannot delete or update a parent row: a foreign key constraint fails

Question

For some reason a user cannot delete a Loan request if it has a bid placed on it, it was working before but when I linked loan requst with bidding on them. I have been getting this error, I can't even delete it in phpmyadmin (mysql), unless I delete the bids associated with the loan request.

Error.

Illuminate\Database\QueryException SQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row: a foreign key constraint fails (holdings.bids, CONSTRAINT bids_loan_id_foreign FOREIGN KEY (loan_id) REFERENCES loan_request (id)) (SQL: delete from loan_request where id = 4)

Image showing sql error

my Schemas;

Loan_request

Schema::create('loan_request', function (Blueprint $table) {
        $table->id();
        $table->unsignedBigInteger('users_id');
        $table->integer('LoanType');
        $table->Biginteger('amount');
        $table->string('PayType');
        $table->integer('IntervalPay');
        $table->string('GracePeriod');
        $table->timestamps();
        $table->foreign('users_id')
        ->references('id')->on('users')->ondelete('cascade');
    });

my Bids schema

Schema::create('bids', function (Blueprint $table) {
        $table->id();
        $table->unsignedBigInteger('loan_id');
        $table->unsignedBigInteger('user_id');
        $table->decimal('interest');
        $table->string('PayType');
        $table->integer('IntervalPay');
        $table->string('GracePeriod');
        $table->timestamps();
        $table->foreign('user_id')
        ->references('id')->on('users')->ondelete('cascade');
        $table->foreign('loan_id')
        ->references('id')->on('loan_request')->ondelete('cascade');
    });

And the responsible Controller; Loancontroller

function delete($id)
{
    Loan_requests::find($id)->delete();
    session()->flash('status','Loan Request deleted successfully');
    return redirect('beg');
}

config/database.php

'connections' => [

    'mysql' => [
        'driver' => 'mysql',
        'url' => env('DATABASE_URL'),
        'host' => env('DB_HOST', '127.0.0.1'),
        'port' => env('DB_PORT', '3306'),
        'database' => env('DB_DATABASE', 'forge'),
        'username' => env('DB_USERNAME', 'forge'),
        'password' => env('DB_PASSWORD', ''),
        'unix_socket' => env('DB_SOCKET', ''),
        'charset' => 'utf8mb4',
        'collation' => 'utf8mb4_unicode_ci',
        'prefix' => '',
        'prefix_indexes' => true,
        'strict' => true,
        'engine' => null,
        'options' => extension_loaded('pdo_mysql') ? array_filter([
            PDO::MYSQL_ATTR_SSL_CA => env('MYSQL_ATTR_SSL_CA'),
        ]) : [],
    ]

    
],

Answer 1

first, delete from bid table

bids::where('bids.loan_id', $id)->delete();

After that

Loan_requests::find($id)->delete();
session()->flash('status','Loan Request deleted successfully');
return redirect()->back();