Here\'s how I do it:
foo, foo_bar, etc.Consistency is what everyone strongly suggest, the rest is upto you as long as it works.
For beginners its easy to get carried away and we name whatever we want at that time. This make sense at that point but a headache later.
foo foobar or foo_bar is great.
We name our table straight forward as much as possible and only use underscore if they are two different words. studentregistration to student_registration
like @Zbyszek says, having a simple id is more than enough for the auto-increment. The simplier the better. Why do you need foo_id? We had the same problem early on, we named all our columns with the table prefix. like foo_id, foo_name, foo_age. We dropped the tablename now and kept only the col as short as possible.
Since we are using just an id for PK we will be using foo_bar_fk (tablename is unique, folowed by the unique PK, followed by the _fk) as foreign key. We don't add id to the col name because it is said that the name 'id' is always the PK of the given table. So we have just the tablename and the _fk at the end.
For constrains we remove all underscores and join with camelCase (tablename + Colname + Fk) foobarUsernameFk (for username_fk col). It's just a way we are following. We keep a documentation for every names structures.
When keeping the col name short, we should also keep an eye on the RESTRICTED names.
+------------------------------------+
| foobar |
+------------------------------------+
| id (PK for the current table) |
| username_fk (PK of username table) |
| location (other column) |
| tel (other column) |
+------------------------------------+