Is it necessary or beneficial to use a "stuff.whatever" naming convention in MySQL?

I'm working on a MySQL database for a social network site I'm building, and so far it's been a great learning experience. However, there has been one thing in particular that's always confused me.

When seeking answers to a partic开发者_C百科ular issue, I see so many examples that use dots in their naming conventions in their MySQL queries. For example:

SELECT c.id, c.comment, c.user_id, u.username, u.photo
FROM (comments c)
JOIN users u ON c.user_id = u.id
WHERE c.topic_id = 9

and here is another example:

SELECT fb.auto_id, fb.user_id, fb.bulletin, fb.subject, fb.color, fb.submit_date, fru.disp_name, fru.pic_url
FROM friend_bulletin AS fb
LEFT JOIN friend_friend AS ff ON fb.user_id = ff.userid
LEFT JOIN friend_reg_user AS fru ON fb.user_id = fru.auto_id
WHERE (
ff.friendid =1
AND ff.status =1
)
LIMIT 0 , 30

Is there a particular benefit to using the dots in the names? As someone who comes from doing a lot of CSS work, at first glance the dots appear to me as some kind of association between different things, but what are they for here?

I suppose I just want to make sure I'm not making my database structure/queries less efficient by not using this 'dot' naming convention. If someone could explain to me in laymen's terms what they are used for, I'd really appreciate it.

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stuff.whatever should be thought of as table_name.column_name. You're explicitly associating each column reference with the table it belongs to which, IMHO, is a best practice to follow.

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You shouldn't think of the dots as being part of a "naming convention." The functionality is more similar to calling an attribute on an object.

In the case of stuff.whatever 'stuff' represents the database table and whatever represents the data in a column called 'whatever' in the database.

If you've seen a column referenced without the table portion, it is because the user is expecting mysql to figure out which column they mean.

If there is only one table in the query with a column of that name, mysql can do it, no problem.

But, for example, you have a "facebook" table and a "twitter" table and you join them through a query because they both have a "user_id" column or something, and they BOTH have an "avatar_image" column and you didn't specify the table, mysql would raise en error telling you it didn't know exactly what you were asking for.

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There is nothing wrong with using full name conventions, however, if you have long table, field names, it is easier to use alias for readability purpose.