Database Reference
In-Depth Information
my
$dbh
=
Cookbook::
connect
();
# Collect parameters that determine where we are in the display and
# verify that they are integers.
# Default to beginning of result set, 10 records/page if parameters
# are missing/malformed.
my
$start
=
param
(
"start"
);
$start
=
1
if
!
defined
(
$start
)
||
$start
!~
/^\d+$/
||
$start
<
1
;
my
$per_page
=
param
(
"per_page"
);
$per_page
=
10
if
!
defined
(
$per_page
)
||
$per_page
!~
/^\d+$/
||
$per_page
<
1
;;
# If start > 1, then we'll need a live "previous page" link.
# To determine whether there is a next page, try to select one more
# record than we need. If we get that many, display only the first
# $per_page records, but add a live "next page" link.
# Select the records in the current page of the result set, and
# attempt to get an extra record. (If we get the extra one, we
# won't display it, but its presence tells us there is a next
# page.)
my
$stmt
=
sprintf
(
"SELECT name, abbrev, statehood, pop
FROM states
ORDER BY name LIMIT %d,%d"
,
$start
-
1
,
# number of records to skip
$per_page
+
1
);
# number of records to select
my
$tbl_ref
=
$dbh
->
selectall_arrayref
(
$stmt
);
$dbh
->
disconnect
();
# Display results as HTML table
my
@rows
;
push
(
@rows
,
Tr
(
th
([
"Name"
,
"Abbreviation"
,
"Statehood"
,
"Population"
])));
for
(
my
$i
=
0
;
$i
<
$per_page
&&
$i
<
@
{
$tbl_ref
};
$i
++
)
{
# get data values in row $i
my
@cells
=
@
{
$tbl_ref
->
[
$i
]};
# get data values in row $i
# map values to HTML-encoded values, or to if null/empty
@cells
=
map
{
defined
(
$_
)
&&
$_
ne
""
?
escapeHTML
(
$_
) :
" "
}
@cells
;
# add cells to table
push
(
@rows
,
Tr
(
td
(
\
@cells
)));
}
$page
.=
table
({
-
border
=>
1
},
@rows
)
.
br
();
