Hi,
thanks for your answer. I will read that article carrefully.
But I should have been more precise in my question. I want to create new content in the right way (if there is at least one) in drupal 7. I think I must use entity if I understand right. But I don't want to use field api. I don't want to have as many tables as fields in my new content. I cannot understand how someone can have to that strange stuff.
Manage data in a database is a hard work and for sure field api is a great work but it's also a bloatware and a nightmare with a large site. I have to maintain a large site and there's severals hundred of tables but with contents no so different. So even simple pages have severals hundred of queries. My site is not so complicated. Did developers who made the site missed something ?
Don't misunderstand me, I like drupal. I hope drupal 8 comming soon. But I really think some api must not be used.
Nicolas