A neat way to parse a query only once per script, if the query is done inside a function:
<?php
function querySomething($conn, $id)
{
static $stmt;
if (is_null($stmt)) {
$stmt = oci_parse($conn, 'select * from t where pk = :id');
}
oci_bind_by_name($stmt, ':id', $id, -1);
oci_execute($stmt, OCI_DEFAULT);
return oci_fetch_array($stmt, OCI_ASSOC);
}
?>
With the static variable, the statment handle isn't closed after the function has terminated. Very nice for functions that are called e.g. in loops. Unfortunately this only works for static sql. If you have dynamic sql, you can do the following:
<?php
function querySomething($conn, $data)
{
static $stmt = array();
$first = true;
$query = 'select * from t';
foreach ($data as $key => $value) {
if ($first) {
$first = false;
$query .= ' where ';
} else {
$query .= ' and ';
}
$query .= "$key = :b$key";
}
$queryhash = md5($query);
if (is_null($stmt[$queryhash])) {
$stmt[$queryhash] = oci_parse($conn, $query);
}
foreach ($data as $key => $value) {
// don't use $value, because we bind memory addresses here.
// this would result in every bind pointing at the same value after foreach
oci_bind_by_name($stmt[$queryhash], ":b$key", $data[$key], -1);
}
oci_execute($stmt[$queryhash], OCI_DEFAULT);
return oci_fetch_array($stmt[$queryhash], OCI_ASSOC);
}
?>
oci_parse
(PHP 5, PECL OCI8 >= 1.1.0)
oci_parse — 実行のために Oracle の文をパースする
説明
resource oci_parse
( resource $connection
, string $query
)
connection を使って query をパースし、ステートメント ID を返します。この ID は、oci_bind_by_name(), oci_execute() や他の関数で使用されます。
返り値
成功した場合にステートメントハンドル、あるいはエラー時に or FALSE を返します。
注意
注意: この関数は query を検証 しません。 query が有効な SQL あるいは PL/SQL 文かどうかを検証する唯一の方法 - それは実行することです。
注意: PHP バージョン 5.0.0 以前では、代わりに ociparse() を使用しなければなりません。 まだこの名前を使用することができ、下位互換性のため oci_parse() への別名として残されていますが、 推奨されません。
oci_parse
michael dot virnstein at brodos dot de
04-Dec-2007 04:43
04-Dec-2007 04:43
27-Jan-2006 12:05
one of the most things that is done wrong with oracle is the following.
Cosider:
<?php
$dbh = ocilogon('user', 'pass', 'db');
for ($i = 0; $i<=10; $i++) {
$sth = ociparse($dbh, 'SELECT * FROM T WHERE x = :x');
ocibindbyname($sth, ':x', $i, -1);
ociexecute($sth, OCI_DEFAULT);
if (ocifetchrow($sth, $row, OCI_ASSOC+OCI_RETURN_NULLS)) {
var_dump($row);
}
}
ocilogoff($dbh);
?>
Problem here is, that you parse the same statement over and over and that'll cost ressources and will introduce many wait events. This problem will increase exponentially with the number of users using your system. That's one of the things besides not using bind variables that will prevent your application from scaling well.
The right approach:
<?php
$dbh = ocilogon('user', 'pass', 'db');
$sth = ociparse($dbh, 'SELECT * FROM T WHERE x = :x');
for ($i = 0; $i<=10; $i++) {
ocibindbyname($sth, ':x', $i, -1);
ociexecute($sth, OCI_DEFAULT);
if (ocifetchrow($sth, $row, OCI_ASSOC+OCI_RETURN_NULLS)) {
var_dump($row);
}
}
ocilogoff($dbh);
?>
Now we are parsing the statement once and using it as often as possible.
When your using Oracle, create proper indexes, use bind variables and parse once and execute often. Not doing so will get you into trouble when more than a few users are working with your application simultaneously.
kurt at kovac dot ch
04-May-2004 03:40
04-May-2004 03:40
For those that are having trouble with error checking, i have noticed on a lot of sites that people are trying to check the statement handle for error messages with OCIParse. Since the statement handle ($sth) is not created yet, you need to check the database handle ($dbh) for any errors with OCIParse. For example:
instead of:
<?php
$stmt = OCIParse($conn, $query);
if (!$stmt) {
$oerr = OCIError($stmt);
echo "Fetch Code 1:".$oerr["message"];
exit;
}
?>
use:
<?php
$stmt = OCIParse($conn, $query);
if (!$stmt) {
$oerr = OCIError($conn);
echo "Fetch Code 1:".$oerr["message"];
exit;
}
?>
Hope this helps someone.
jicurito at hotmail dot com
10-Dec-2003 12:41
10-Dec-2003 12:41
regarding egypt note on double quotes, the reason for that behaviour is that Oracle treats things with double quotes as identifiers on a given statement... using single quotes won't provoque mistakes...
egypt at nmt dot edu
15-Oct-2003 02:31
15-Oct-2003 02:31
Whereas MySQL doesn't care what kind of quotes are around a LIKE clause, ociexecute gives the error:
ociexecute(): OCIStmtExecute: ORA-00904: "NM": invalid identifier
for the following.
<?php
$sql = "SELECT * FROM addresses "
. "WHERE state LIKE \"NM\""; // error!
$stmt = ociparse($conn, $sql);
ociexecute($stmt);
?>
it's fine if you just use single quotes:
. "WHERE state LIKE 'NM'";
but i think it's interesting that ociparse doesn't say anything
mwd at modulo3 dot de
22-Dec-2000 03:21
22-Dec-2000 03:21
if you're using "complex" statements e.g such having calls to build in oracle functions in the select list (as in example below), I did not find any other way as using the "AS <Name>" clause to being able to output the functions outcome using ociresult
example:
<?php
ociparse($conn,"select EMPNO, LPAD(' ', 2*(LEVEL-1)) || ENAME AS COMPLETE_FANTASY_NAME, JOB, HIREDATE from scott.emp start with job='MANAGER' connect by PRIOR EMPNO = MGR");
echo ociresult $stmt,"COMPLETE_FANTASY_NAME")." ";
?>
BTW: I also found out by TAE that "COMPLETE_FANATASY_NAME" might not be "complete fantasy" as it has to be all capital letters.
