When you want to call stored function (and want to read its result) which executes DML queries (insert, update, delete) inside its body you can't use "select your_stored_function(:param1, :param2) from dual" because you will receive "ORA-14551: cannot perform a DML operation inside a query" error.
In order to call such function and get its result you need to wrap it into nested procedure with OUT parameter like this:
DECLARE
PROCEDURE caller(return_value OUT NUMBER) AS
BEGIN
return_value := your_stored_function(:param1, :param2);
END;
BEGIN
caller(:return_value);
END;
and bind to :return_value variable to get the result of function.
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
$connection
, string $sql_text
)
connection
を使って sql_text 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。
ステートメント ID を解放するには、
oci_free_statement() を使うか、あるいは
変数に NULL を代入します。
パラメータ
-
connection -
oci_connect()、oci_pconnect() あるいは oci_new_connect() が返す Oracle 接続 ID。
-
sql_text -
SQL あるいは PL/SQL ステートメント。
SQL の最後にセミコロン (";") をつけては いけません。一方、PL/SQL ステートメントの最後はセミコロン (";") を つけなければなりません。
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 FALSE を返します。
例
例1 oci_parse() での SQL 文の例
<?php
$conn = oci_connect('hr', 'welcome', 'localhost/XE');
// パースします。SQL 文の最後にはセミコロンがないことに注意しましょう
$stid = oci_parse($conn, 'SELECT * FROM employees');
oci_execute($stid);
echo "<table border='1'>\n";
while ($row = oci_fetch_array($stid, OCI_ASSOC+OCI_RETURN_NULLS)) {
echo "<tr>\n";
foreach ($row as $item) {
echo " <td>" . ($item !== null ? htmlentities($item, ENT_QUOTES) : " ") . "</td>\n";
}
echo "</tr>\n";
}
echo "</table>\n";
?>
例2 oci_parse() での PL/SQL の例
<?php
/*
この PHP プログラムを実行する前に、SQL*Plus や SQL Developer で
ストアドプロシージャを作っておきます
CREATE OR REPLACE PROCEDURE myproc(p1 IN NUMBER, p2 OUT NUMBER) AS
BEGIN
p2 := p1 * 2;
END;
*/
$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
$e = oci_error();
trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
}
$p1 = 8;
// PL/SQL プログラムをパースするには、文字列の最後にセミコロンが必要です
$stid = oci_parse($conn, 'begin myproc(:p1, :p2); end;');
oci_bind_by_name($stid, ':p1', $p1);
oci_bind_by_name($stid, ':p2', $p2, 40);
oci_execute($stid);
print "$p2\n"; // 16 と表示します
oci_free_statement($stid);
oci_close($conn);
?>
注意
注意:
この関数は
sql_textを検証 しません。sql_textが有効な SQL あるいは PL/SQL 文かどうかを検証する唯一の方法 - それは実行することです。
注意:
PHP 5.0.0 より前のバージョンでは、かわりに ociparse() を使用します。現在のバージョンでは、古い関数名もまだ使えます。 しかし、これは廃止予定であり非推奨です。
A neat way to parse a query only once per script, if the query is done inside a function:
<?php
function querySomething($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);
}
?>
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($dbh);
?>
Now we are parsing the statement once and using it as often as possible.
When your using Oracle, create proper indexes, use bind variables and parse once and execute often. Not doing so will get you into trouble when more than a few users are working with your application simultaneously.
For those that are having trouble with error checking, i have noticed on a lot of sites that people are trying to check the statement handle for error messages with OCIParse. Since the statement handle ($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.
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...
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
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.
