Some considerations on yii2:
it important to have installed composer to be able to install yii2 from a file?.
I do not have installed composer.
When I install yii2 from the basic file, that is, I decompress it and I do him the changes in config/db it is not executed.
I need to learn how to utilize yii2, since all my experience has been with yii1 to the version 1,1,17, where you have elaborated some systems with no difficulty.