What does the * asterisk mean in a mysql statement?

Question

Ex. mysql_query("SELECT * FROM members WHERE id='$id');

Answer 1

It means select all columns in the table.

Answer 2

It means that you are selecting every column in the table. This is something you should avoid in production environments though because it causes a bit of overhead and things tend to break when you alter your tables and use the * selector.

A better way to do this is to select only the columns you need each time, like the following example:

SELECT `id`, `firstName`, `lastName` FROM members WHERE id='$id'

Answer 3

Select ALL fields from some table.