Q. What is a blog?
A.
A blog is a website created by just
about anyone where entries are made in
journal or diary style and displayed in
a format with the most recent entry
displayed first. Blogs allow anyone to
expound on subjects like news items,
food, politics, or just about anything
else.
Some bloggers use them as their personal
diaries and then get comments from the
readers. Most blogs combine text
graphics and usually links to other
blogs and media related to its topic.
Some blogs are informative and might be
interesting to one specifically
interested in the blogs subject.
However, as you may expect, many of the
million or so available contain little
fact, and are filled with the writers
opinions.
The ability for readers to leave
interactive comments is what makes a
blog a blog. Most blogs are are composed
primarily of text. If they focus on
pictures they may be called a photoblog,
sketchblog, or vblog (Video Blog). If
they provide audio in MP3 or other
medium, they are commonly referred to as
a podcast. The term "blog" is probably
derived from "Web log." "Blog" and in is
routinely used as noun or verb. An old
term closely related to a blog, from
before the Internet, might be the "Soap
Box" of earlier days.
Q.
What is meant by an "Unsafe Expression"?
A.
From what I can tell, this is making
a reference to an error message that may
appear in Microsoft Access when a
database is opened. The error message
looks like this:
First, the delimitation of an
"expression" as related to computer
programming.
"An expression in
a programming language is a
combination of values, variables,
operators, and functions that are
interpreted or evaluated according
to the particular rules of
precedence and of association for a
particular programming language,
which computes and then produces or
returns, in a stateful environment
another value. The expression is
said to evaluate to that value. As
in mathematics, the expression is or
can be said to have its evaluated
value; the expression is a
representation of that value."
An example of an expression is one
that is used for the feature that
allows you to create page numbers
like" Page 3 of 5". Every time you
change pages, the expression is
evaluated to determine what page you
are on and what is the total number
of pages.
The page you are on can change;
pages can be inserted or deleted;
and the total number of pages can
vary. An expression is used on each
page that evaluates and returns this
information when pages change rather
than hard coding the actual page
number that would have to be changed
manually when additions or
reductions were made.
A
person, with less than honorable
intentions, could use an expression
to do bad things to you, your
computer and the database. Access
can check for these and if one is
found, block it. This however, can
take time while a database is
checked making the opening and use
of the database slower. Therefore,
this check for unsafe expressions is
usually turned off by default when
Access is installed, thus the
information message.
