Database Reference
In-Depth Information
stmt
=
"SELECT phrase_val FROM phrase ORDER BY phrase_val"
dbh
.
execute
(
stmt
)
do
|
sth
|
sth
.
fetch
do
|
row
|
# make sure that the value is a string
phrase
=
row
[
0
].
to_s
# URL-encode the phrase value for use in the URL
url
=
"/cgi-bin/mysearch.rb?phrase="
+
CGI
.
escape
(
phrase
)
# HTML-encode the phrase value for use in the link label
label
=
CGI
.
escapeHTML
(
phrase
)
page
<<
cgi
.
a
(
"href"
=>
url
) {
label
}
+
cgi
.
br
end
end
page
is used here as a variable that “accumulates” page content and that eventually you
pass to
cgi.out
to display the page.
PHP.
In PHP, the
htmlspecialchars()
and
urlencode()
functions perform HTML-
encoding and URL-encoding. Use them as follows:
$stmt
=
"SELECT phrase_val FROM phrase ORDER BY phrase_val"
;
$sth
=
$dbh
->
query
(
$stmt
);
while
(
list
(
$phrase
)
=
$sth
->
fetch
(
PDO
::
FETCH_NUM
))
{
# URL-encode the phrase value for use in the URL
$url
=
"/mcb/mysearch.php?phrase="
.
urlencode
(
$phrase
);
# HTML-encode the phrase value for use in the link label
$label
=
htmlspecialchars
(
$phrase
);
printf
(
'<a href="%s">%s</a><br />'
,
$url
,
$label
);
}
Python.
In Python, the
cgi
and
urllib
modules contain the relevant encoding methods.
cgi.escape()
and
urllib.quote()
perform HTML-encoding and URL-encoding.
However, both methods raise an exception unless the argument is a string. To deal with
this, apply the
str()
method to any argument that might not be a string, to force it to
string form and convert
None
to the string
"None"
. (If you want
None
to convert to the
empty string, you must test for it explicitly.) For example:
import
cgi
import
urllib
stmt
=
"SELECT phrase_val FROM phrase ORDER BY phrase_val"
cursor
=
conn
.
cursor
()
cursor
.
execute
(
stmt
)
for
(
phrase
,)
in
cursor
:
# make sure that the value is a string
phrase
=
str
(
phrase
)
# URL-encode the phrase value for use in the URL
url
=
"/cgi-bin/mysearch.py?phrase="
+
urllib
.
quote
(
phrase
)
# HTML-encode the phrase value for use in the link label
label
=
cgi
.
escape
(
phrase
,
1
)
