#load fixtures from UsersFixture class with default namespace "tests\unit\fixtures"
yii fixture/load User
#also a short version of this command (generate action is default)
yii fixture User
#load all fixtures
yii fixture "*"
#load all fixtures except User
yii fixture "*, -User"
#load fixtures with different namespace.
yii fixture/load User --namespace=alias\my\custom\namespace\goes\here
The unload sub-command can be used similarly to unload fixtures.