The following font conventions have been used throughout the book:
Constant
width
Used for program listings, as well as within paragraphs to refer to program elements such as variable or function names.
Constant width bold
Used to indicate text that you type when running commands.
Constant
width
italic
Used to indicate variable input; you should substitute a value of your own choosing.
- Italic
Used for URLs, hostnames, names of directories and files, Unix commands and options, and occasionally for emphasis.
Commands often are shown with a prompt to illustrate the context in
which they are used. Commands that you issue from the command line
are shown with a %
prompt:
% chmod 600 my.cnf
That prompt is one that Unix users are used to seeing, but it
doesn’t necessarily signify that a command will work
only under Unix. Unless indicated otherwise, commands shown with a
%
prompt generally should work under Windows, too.
If you should run a command under Unix as the root
user, the prompt is #
instead:
# chkconfig --add tomcat4
For commands that are specific only to Windows, the
C:\>
prompt is used:
C:\> copy C:\mysql\lib\cygwinb19.dll C:\Windows\System
SQL statements that are issued from within the
mysql client program are shown with a
mysql>
prompt and terminated with a semicolon:
mysql> SELECT * FROM my_table;
For examples that show a query result as you would see it when using
mysql, I sometimes truncate the output, using an
ellipsis (...
) to indicate that the result
consists of more rows than are shown. The following query produces
many rows of output, of which those in the middle have been omitted:
mysql> SELECT name, abbrev FROM states ORDER BY name;
+----------------+--------+
| name | abbrev |
+----------------+--------+
| Alabama | AL |
| Alaska | AK |
| Arizona | AZ |
...
| West Virginia | WV |
| Wisconsin | WI |
| Wyoming | WY |
+----------------+--------+
Examples that just show the syntax for SQL statements do not include
the mysql>
prompt, but they do include
semicolons as necessary to make it clear where statements end. For
example, this is a single statement:
CREATE TABLE t1 (i INT) SELECT * FROM t2;
But this example represents two statements:
CREATE TABLE t1 (i INT); SELECT * FROM t2;
The semicolon is a notational convenience used within mysql as a statement terminator. But it is not part of SQL itself, so when you issue SQL statements from within programs that you write (for example, using Perl or Java), you should not include terminating semicolons.
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