upgrade composer version
composer self-update
update particular package composer
composer update doctrine/doctrine-fixtures-bundle
composer install without dependencies
composer install --ignore-platform-reqs
php composer update
php composer.phar update
upgrade composer
To update composer command just find location of composer.phar and update as:
where composer #Retrieves you location of your composer.phar
cd path_to_composer.phar #Move to directory with composer.phar
php composer.phar self-update #Update your composer
composer add package
composer require name-of-package