/lib/dml/oci_native_moodle_database.php
PHP | 1811 lines | 1197 code | 169 blank | 445 comment | 161 complexity | 0ee0774761a30e7596b2284a89639e2d MD5 | raw file
Possible License(s): GPL-3.0, LGPL-2.1, BSD-3-Clause, Apache-2.0
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- <?php
- // This file is part of Moodle - http://moodle.org/
- //
- // Moodle is free software: you can redistribute it and/or modify
- // it under the terms of the GNU General Public License as published by
- // the Free Software Foundation, either version 3 of the License, or
- // (at your option) any later version.
- //
- // Moodle is distributed in the hope that it will be useful,
- // but WITHOUT ANY WARRANTY; without even the implied warranty of
- // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- // GNU General Public License for more details.
- //
- // You should have received a copy of the GNU General Public License
- // along with Moodle. If not, see <http://www.gnu.org/licenses/>.
- /**
- * Native oci class representing moodle database interface.
- *
- * @package core_dml
- * @copyright 2008 Petr Skoda (http://skodak.org)
- * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
- */
- defined('MOODLE_INTERNAL') || die();
- require_once(__DIR__.'/moodle_database.php');
- require_once(__DIR__.'/oci_native_moodle_recordset.php');
- require_once(__DIR__.'/oci_native_moodle_temptables.php');
- /**
- * Native oci class representing moodle database interface.
- *
- * One complete reference for PHP + OCI:
- * http://www.oracle.com/technology/tech/php/underground-php-oracle-manual.html
- *
- * @package core_dml
- * @copyright 2008 Petr Skoda (http://skodak.org)
- * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
- */
- class oci_native_moodle_database extends moodle_database {
- protected $oci = null;
- /** @var To store stmt errors and enable get_last_error() to detect them.*/
- private $last_stmt_error = null;
- /** @var Default value initialised in connect method, we need the driver to be present.*/
- private $commit_status = null;
- /** @var To handle oci driver default verbosity.*/
- private $last_error_reporting;
- /** @var To store unique_session_id. Needed for temp tables unique naming.*/
- private $unique_session_id;
- /**
- * Detects if all needed PHP stuff installed.
- * Note: can be used before connect()
- * @return mixed true if ok, string if something
- */
- public function driver_installed() {
- if (!extension_loaded('oci8')) {
- return get_string('ociextensionisnotpresentinphp', 'install');
- }
- return true;
- }
- /**
- * Returns database family type - describes SQL dialect
- * Note: can be used before connect()
- * @return string db family name (mysql, postgres, mssql, oracle, etc.)
- */
- public function get_dbfamily() {
- return 'oracle';
- }
- /**
- * Returns more specific database driver type
- * Note: can be used before connect()
- * @return string db type mysqli, pgsql, oci, mssql, sqlsrv
- */
- protected function get_dbtype() {
- return 'oci';
- }
- /**
- * Returns general database library name
- * Note: can be used before connect()
- * @return string db type pdo, native
- */
- protected function get_dblibrary() {
- return 'native';
- }
- /**
- * Returns localised database type name
- * Note: can be used before connect()
- * @return string
- */
- public function get_name() {
- return get_string('nativeoci', 'install');
- }
- /**
- * Returns localised database configuration help.
- * Note: can be used before connect()
- * @return string
- */
- public function get_configuration_help() {
- return get_string('nativeocihelp', 'install');
- }
- /**
- * Diagnose database and tables, this function is used
- * to verify database and driver settings, db engine types, etc.
- *
- * @return string null means everything ok, string means problem found.
- */
- public function diagnose() {
- return null;
- }
- /**
- * Connect to db
- * Must be called before other methods.
- * @param string $dbhost The database host.
- * @param string $dbuser The database username.
- * @param string $dbpass The database username's password.
- * @param string $dbname The name of the database being connected to.
- * @param mixed $prefix string means moodle db prefix, false used for external databases where prefix not used
- * @param array $dboptions driver specific options
- * @return bool true
- * @throws dml_connection_exception if error
- */
- public function connect($dbhost, $dbuser, $dbpass, $dbname, $prefix, array $dboptions=null) {
- if ($prefix == '' and !$this->external) {
- //Enforce prefixes for everybody but mysql
- throw new dml_exception('prefixcannotbeempty', $this->get_dbfamily());
- }
- if (!$this->external and strlen($prefix) > 2) {
- //Max prefix length for Oracle is 2cc
- $a = (object)array('dbfamily'=>'oracle', 'maxlength'=>2);
- throw new dml_exception('prefixtoolong', $a);
- }
- $driverstatus = $this->driver_installed();
- if ($driverstatus !== true) {
- throw new dml_exception('dbdriverproblem', $driverstatus);
- }
- // Autocommit ON by default.
- // Switching to OFF (OCI_DEFAULT), when playing with transactions
- // please note this thing is not defined if oracle driver not present in PHP
- // which means it can not be used as default value of object property!
- $this->commit_status = OCI_COMMIT_ON_SUCCESS;
- $this->store_settings($dbhost, $dbuser, $dbpass, $dbname, $prefix, $dboptions);
- unset($this->dboptions['dbsocket']);
- // NOTE: use of ', ", /Â and \ is very problematic, even native oracle tools seem to have
- // problems with these, so just forget them and do not report problems into tracker...
- if (empty($this->dbhost)) {
- // old style full address (TNS)
- $dbstring = $this->dbname;
- } else {
- if (empty($this->dboptions['dbport'])) {
- $this->dboptions['dbport'] = 1521;
- }
- $dbstring = '//'.$this->dbhost.':'.$this->dboptions['dbport'].'/'.$this->dbname;
- }
- ob_start();
- if (empty($this->dboptions['dbpersist'])) {
- $this->oci = oci_new_connect($this->dbuser, $this->dbpass, $dbstring, 'AL32UTF8');
- } else {
- $this->oci = oci_pconnect($this->dbuser, $this->dbpass, $dbstring, 'AL32UTF8');
- }
- $dberr = ob_get_contents();
- ob_end_clean();
- if ($this->oci === false) {
- $this->oci = null;
- $e = oci_error();
- if (isset($e['message'])) {
- $dberr = $e['message'];
- }
- throw new dml_connection_exception($dberr);
- }
- // Make sure moodle package is installed - now required.
- if (!$this->oci_package_installed()) {
- try {
- $this->attempt_oci_package_install();
- } catch (Exception $e) {
- // Ignore problems, only the result counts,
- // admins have to fix it manually if necessary.
- }
- if (!$this->oci_package_installed()) {
- throw new dml_exception('dbdriverproblem', 'Oracle PL/SQL Moodle support package MOODLELIB is not installed! Database administrator has to execute /lib/dml/oci_native_moodle_package.sql script.');
- }
- }
- // get unique session id, to be used later for temp tables stuff
- $sql = 'SELECT DBMS_SESSION.UNIQUE_SESSION_ID() FROM DUAL';
- $this->query_start($sql, null, SQL_QUERY_AUX);
- $stmt = $this->parse_query($sql);
- $result = oci_execute($stmt, $this->commit_status);
- $this->query_end($result, $stmt);
- $records = null;
- oci_fetch_all($stmt, $records, 0, -1, OCI_FETCHSTATEMENT_BY_ROW);
- oci_free_statement($stmt);
- $this->unique_session_id = reset($records[0]);
- //note: do not send "ALTER SESSION SET NLS_NUMERIC_CHARACTERS='.,'" !
- // instead fix our PHP code to convert "," to "." properly!
- // Connection stabilised and configured, going to instantiate the temptables controller
- $this->temptables = new oci_native_moodle_temptables($this, $this->unique_session_id);
- return true;
- }
- /**
- * Close database connection and release all resources
- * and memory (especially circular memory references).
- * Do NOT use connect() again, create a new instance if needed.
- */
- public function dispose() {
- parent::dispose(); // Call parent dispose to write/close session and other common stuff before closing connection
- if ($this->oci) {
- oci_close($this->oci);
- $this->oci = null;
- }
- }
- /**
- * Called before each db query.
- * @param string $sql
- * @param array array of parameters
- * @param int $type type of query
- * @param mixed $extrainfo driver specific extra information
- * @return void
- */
- protected function query_start($sql, array $params=null, $type, $extrainfo=null) {
- parent::query_start($sql, $params, $type, $extrainfo);
- // oci driver tents to send debug to output, we do not need that ;-)
- $this->last_error_reporting = error_reporting(0);
- }
- /**
- * Called immediately after each db query.
- * @param mixed db specific result
- * @return void
- */
- protected function query_end($result, $stmt=null) {
- // reset original debug level
- error_reporting($this->last_error_reporting);
- if ($stmt and $result === false) {
- // Look for stmt error and store it
- if (is_resource($stmt)) {
- $e = oci_error($stmt);
- if ($e !== false) {
- $this->last_stmt_error = $e['message'];
- }
- }
- oci_free_statement($stmt);
- }
- parent::query_end($result);
- }
- /**
- * Returns database server info array
- * @return array Array containing 'description' and 'version' info
- */
- public function get_server_info() {
- static $info = null; // TODO: move to real object property
- if (is_null($info)) {
- $this->query_start("--oci_server_version()", null, SQL_QUERY_AUX);
- $description = oci_server_version($this->oci);
- $this->query_end(true);
- preg_match('/(\d+\.)+\d+/', $description, $matches);
- $info = array('description'=>$description, 'version'=>$matches[0]);
- }
- return $info;
- }
- /**
- * Converts short table name {tablename} to real table name
- * supporting temp tables ($this->unique_session_id based) if detected
- *
- * @param string sql
- * @return string sql
- */
- protected function fix_table_names($sql) {
- if (preg_match_all('/\{([a-z][a-z0-9_]*)\}/', $sql, $matches)) {
- foreach($matches[0] as $key=>$match) {
- $name = $matches[1][$key];
- if ($this->temptables && $this->temptables->is_temptable($name)) {
- $sql = str_replace($match, $this->temptables->get_correct_name($name), $sql);
- } else {
- $sql = str_replace($match, $this->prefix.$name, $sql);
- }
- }
- }
- return $sql;
- }
- /**
- * Returns supported query parameter types
- * @return int bitmask of accepted SQL_PARAMS_*
- */
- protected function allowed_param_types() {
- return SQL_PARAMS_NAMED;
- }
- /**
- * Returns last error reported by database engine.
- * @return string error message
- */
- public function get_last_error() {
- $error = false;
- // First look for any previously saved stmt error
- if (!empty($this->last_stmt_error)) {
- $error = $this->last_stmt_error;
- $this->last_stmt_error = null;
- } else { // Now try connection error
- $e = oci_error($this->oci);
- if ($e !== false) {
- $error = $e['message'];
- }
- }
- return $error;
- }
- /**
- * Prepare the statement for execution
- * @throws dml_connection_exception
- * @param string $sql
- * @return resource
- */
- protected function parse_query($sql) {
- $stmt = oci_parse($this->oci, $sql);
- if ($stmt == false) {
- throw new dml_connection_exception('Can not parse sql query'); //TODO: maybe add better info
- }
- return $stmt;
- }
- /**
- * Make sure there are no reserved words in param names...
- * @param string $sql
- * @param array $params
- * @return array ($sql, $params) updated query and parameters
- */
- protected function tweak_param_names($sql, array $params) {
- if (empty($params)) {
- return array($sql, $params);
- }
- $newparams = array();
- $searcharr = array(); // search => replace pairs
- foreach ($params as $name => $value) {
- // Keep the name within the 30 chars limit always (prefixing/replacing)
- if (strlen($name) <= 28) {
- $newname = 'o_' . $name;
- } else {
- $newname = 'o_' . substr($name, 2);
- }
- $newparams[$newname] = $value;
- $searcharr[':' . $name] = ':' . $newname;
- }
- // sort by length desc to avoid potential str_replace() overlap
- uksort($searcharr, array('oci_native_moodle_database', 'compare_by_length_desc'));
- $sql = str_replace(array_keys($searcharr), $searcharr, $sql);
- return array($sql, $newparams);
- }
- /**
- * Return tables in database WITHOUT current prefix
- * @param bool $usecache if true, returns list of cached tables.
- * @return array of table names in lowercase and without prefix
- */
- public function get_tables($usecache=true) {
- if ($usecache and $this->tables !== null) {
- return $this->tables;
- }
- $this->tables = array();
- $prefix = str_replace('_', "\\_", strtoupper($this->prefix));
- $sql = "SELECT TABLE_NAME
- FROM CAT
- WHERE TABLE_TYPE='TABLE'
- AND TABLE_NAME NOT LIKE 'BIN\$%'
- AND TABLE_NAME LIKE '$prefix%' ESCAPE '\\'";
- $this->query_start($sql, null, SQL_QUERY_AUX);
- $stmt = $this->parse_query($sql);
- $result = oci_execute($stmt, $this->commit_status);
- $this->query_end($result, $stmt);
- $records = null;
- oci_fetch_all($stmt, $records, 0, -1, OCI_ASSOC);
- oci_free_statement($stmt);
- $records = array_map('strtolower', $records['TABLE_NAME']);
- foreach ($records as $tablename) {
- if ($this->prefix !== false && $this->prefix !== '') {
- if (strpos($tablename, $this->prefix) !== 0) {
- continue;
- }
- $tablename = substr($tablename, strlen($this->prefix));
- }
- $this->tables[$tablename] = $tablename;
- }
- // Add the currently available temptables
- $this->tables = array_merge($this->tables, $this->temptables->get_temptables());
- return $this->tables;
- }
- /**
- * Return table indexes - everything lowercased.
- * @param string $table The table we want to get indexes from.
- * @return array An associative array of indexes containing 'unique' flag and 'columns' being indexed
- */
- public function get_indexes($table) {
- $indexes = array();
- $tablename = strtoupper($this->prefix.$table);
- $sql = "SELECT i.INDEX_NAME, i.UNIQUENESS, c.COLUMN_POSITION, c.COLUMN_NAME, ac.CONSTRAINT_TYPE
- FROM ALL_INDEXES i
- JOIN ALL_IND_COLUMNS c ON c.INDEX_NAME=i.INDEX_NAME
- LEFT JOIN ALL_CONSTRAINTS ac ON (ac.TABLE_NAME=i.TABLE_NAME AND ac.CONSTRAINT_NAME=i.INDEX_NAME AND ac.CONSTRAINT_TYPE='P')
- WHERE i.TABLE_NAME = '$tablename'
- ORDER BY i.INDEX_NAME, c.COLUMN_POSITION";
- $stmt = $this->parse_query($sql);
- $result = oci_execute($stmt, $this->commit_status);
- $this->query_end($result, $stmt);
- $records = null;
- oci_fetch_all($stmt, $records, 0, -1, OCI_FETCHSTATEMENT_BY_ROW);
- oci_free_statement($stmt);
- foreach ($records as $record) {
- if ($record['CONSTRAINT_TYPE'] === 'P') {
- //ignore for now;
- continue;
- }
- $indexname = strtolower($record['INDEX_NAME']);
- if (!isset($indexes[$indexname])) {
- $indexes[$indexname] = array('primary' => ($record['CONSTRAINT_TYPE'] === 'P'),
- 'unique' => ($record['UNIQUENESS'] === 'UNIQUE'),
- 'columns' => array());
- }
- $indexes[$indexname]['columns'][] = strtolower($record['COLUMN_NAME']);
- }
- return $indexes;
- }
- /**
- * Returns detailed information about columns in table. This information is cached internally.
- * @param string $table name
- * @param bool $usecache
- * @return array array of database_column_info objects indexed with column names
- */
- public function get_columns($table, $usecache=true) {
- if ($usecache) {
- $properties = array('dbfamily' => $this->get_dbfamily(), 'settings' => $this->get_settings_hash());
- $cache = cache::make('core', 'databasemeta', $properties);
- if ($data = $cache->get($table)) {
- return $data;
- }
- }
- if (!$table) { // table not specified, return empty array directly
- return array();
- }
- $structure = array();
- // We give precedence to CHAR_LENGTH for VARCHAR2 columns over WIDTH because the former is always
- // BYTE based and, for cross-db operations, we want CHAR based results. See MDL-29415
- // Instead of guessing sequence based exclusively on name, check tables against user_triggers to
- // ensure the table has a 'before each row' trigger to assume 'id' is auto_increment. MDL-32365
- $sql = "SELECT CNAME, COLTYPE, nvl(CHAR_LENGTH, WIDTH) AS WIDTH, SCALE, PRECISION, NULLS, DEFAULTVAL,
- DECODE(NVL(TRIGGER_NAME, '0'), '0', '0', '1') HASTRIGGER
- FROM COL c
- LEFT JOIN USER_TAB_COLUMNS u ON (u.TABLE_NAME = c.TNAME AND u.COLUMN_NAME = c.CNAME AND u.DATA_TYPE = 'VARCHAR2')
- LEFT JOIN USER_TRIGGERS t ON (t.TABLE_NAME = c.TNAME AND TRIGGER_TYPE = 'BEFORE EACH ROW' AND c.CNAME = 'ID')
- WHERE TNAME = UPPER('{" . $table . "}')
- ORDER BY COLNO";
- list($sql, $params, $type) = $this->fix_sql_params($sql, null);
- $this->query_start($sql, null, SQL_QUERY_AUX);
- $stmt = $this->parse_query($sql);
- $result = oci_execute($stmt, $this->commit_status);
- $this->query_end($result, $stmt);
- $records = null;
- oci_fetch_all($stmt, $records, 0, -1, OCI_FETCHSTATEMENT_BY_ROW);
- oci_free_statement($stmt);
- if (!$records) {
- return array();
- }
- foreach ($records as $rawcolumn) {
- $rawcolumn = (object)$rawcolumn;
- $info = new stdClass();
- $info->name = strtolower($rawcolumn->CNAME);
- $info->auto_increment = ((int)$rawcolumn->HASTRIGGER) ? true : false;
- $matches = null;
- if ($rawcolumn->COLTYPE === 'VARCHAR2'
- or $rawcolumn->COLTYPE === 'VARCHAR'
- or $rawcolumn->COLTYPE === 'NVARCHAR2'
- or $rawcolumn->COLTYPE === 'NVARCHAR'
- or $rawcolumn->COLTYPE === 'CHAR'
- or $rawcolumn->COLTYPE === 'NCHAR') {
- $info->type = $rawcolumn->COLTYPE;
- $info->meta_type = 'C';
- $info->max_length = $rawcolumn->WIDTH;
- $info->scale = null;
- $info->not_null = ($rawcolumn->NULLS === 'NOT NULL');
- $info->has_default = !is_null($rawcolumn->DEFAULTVAL);
- if ($info->has_default) {
- // this is hacky :-(
- if ($rawcolumn->DEFAULTVAL === 'NULL') {
- $info->default_value = null;
- } else if ($rawcolumn->DEFAULTVAL === "' ' ") { // Sometimes it's stored with trailing space
- $info->default_value = "";
- } else if ($rawcolumn->DEFAULTVAL === "' '") { // Sometimes it's stored without trailing space
- $info->default_value = "";
- } else {
- $info->default_value = trim($rawcolumn->DEFAULTVAL); // remove trailing space
- $info->default_value = substr($info->default_value, 1, strlen($info->default_value)-2); //trim ''
- }
- } else {
- $info->default_value = null;
- }
- $info->primary_key = false;
- $info->binary = false;
- $info->unsigned = null;
- $info->unique = null;
- } else if ($rawcolumn->COLTYPE === 'NUMBER') {
- $info->type = $rawcolumn->COLTYPE;
- $info->max_length = $rawcolumn->PRECISION;
- $info->binary = false;
- if (!is_null($rawcolumn->SCALE) && $rawcolumn->SCALE == 0) { // null in oracle scale allows decimals => not integer
- // integer
- if ($info->name === 'id') {
- $info->primary_key = true;
- $info->meta_type = 'R';
- $info->unique = true;
- $info->has_default = false;
- } else {
- $info->primary_key = false;
- $info->meta_type = 'I';
- $info->unique = null;
- }
- $info->scale = 0;
- } else {
- //float
- $info->meta_type = 'N';
- $info->primary_key = false;
- $info->unsigned = null;
- $info->unique = null;
- $info->scale = $rawcolumn->SCALE;
- }
- $info->not_null = ($rawcolumn->NULLS === 'NOT NULL');
- $info->has_default = !is_null($rawcolumn->DEFAULTVAL);
- if ($info->has_default) {
- $info->default_value = trim($rawcolumn->DEFAULTVAL); // remove trailing space
- } else {
- $info->default_value = null;
- }
- } else if ($rawcolumn->COLTYPE === 'FLOAT') {
- $info->type = $rawcolumn->COLTYPE;
- $info->max_length = (int)($rawcolumn->PRECISION * 3.32193);
- $info->primary_key = false;
- $info->meta_type = 'N';
- $info->unique = null;
- $info->not_null = ($rawcolumn->NULLS === 'NOT NULL');
- $info->has_default = !is_null($rawcolumn->DEFAULTVAL);
- if ($info->has_default) {
- $info->default_value = trim($rawcolumn->DEFAULTVAL); // remove trailing space
- } else {
- $info->default_value = null;
- }
- } else if ($rawcolumn->COLTYPE === 'CLOB'
- or $rawcolumn->COLTYPE === 'NCLOB') {
- $info->type = $rawcolumn->COLTYPE;
- $info->meta_type = 'X';
- $info->max_length = -1;
- $info->scale = null;
- $info->scale = null;
- $info->not_null = ($rawcolumn->NULLS === 'NOT NULL');
- $info->has_default = !is_null($rawcolumn->DEFAULTVAL);
- if ($info->has_default) {
- // this is hacky :-(
- if ($rawcolumn->DEFAULTVAL === 'NULL') {
- $info->default_value = null;
- } else if ($rawcolumn->DEFAULTVAL === "' ' ") { // Sometimes it's stored with trailing space
- $info->default_value = "";
- } else if ($rawcolumn->DEFAULTVAL === "' '") { // Other times it's stored without trailing space
- $info->default_value = "";
- } else {
- $info->default_value = trim($rawcolumn->DEFAULTVAL); // remove trailing space
- $info->default_value = substr($info->default_value, 1, strlen($info->default_value)-2); //trim ''
- }
- } else {
- $info->default_value = null;
- }
- $info->primary_key = false;
- $info->binary = false;
- $info->unsigned = null;
- $info->unique = null;
- } else if ($rawcolumn->COLTYPE === 'BLOB') {
- $info->type = $rawcolumn->COLTYPE;
- $info->meta_type = 'B';
- $info->max_length = -1;
- $info->scale = null;
- $info->scale = null;
- $info->not_null = ($rawcolumn->NULLS === 'NOT NULL');
- $info->has_default = !is_null($rawcolumn->DEFAULTVAL);
- if ($info->has_default) {
- // this is hacky :-(
- if ($rawcolumn->DEFAULTVAL === 'NULL') {
- $info->default_value = null;
- } else if ($rawcolumn->DEFAULTVAL === "' ' ") { // Sometimes it's stored with trailing space
- $info->default_value = "";
- } else if ($rawcolumn->DEFAULTVAL === "' '") { // Sometimes it's stored without trailing space
- $info->default_value = "";
- } else {
- $info->default_value = trim($rawcolumn->DEFAULTVAL); // remove trailing space
- $info->default_value = substr($info->default_value, 1, strlen($info->default_value)-2); //trim ''
- }
- } else {
- $info->default_value = null;
- }
- $info->primary_key = false;
- $info->binary = true;
- $info->unsigned = null;
- $info->unique = null;
- } else {
- // unknown type - sorry
- $info->type = $rawcolumn->COLTYPE;
- $info->meta_type = '?';
- }
- $structure[$info->name] = new database_column_info($info);
- }
- if ($usecache) {
- $cache->set($table, $structure);
- }
- return $structure;
- }
- /**
- * Normalise values based in RDBMS dependencies (booleans, LOBs...)
- *
- * @param database_column_info $column column metadata corresponding with the value we are going to normalise
- * @param mixed $value value we are going to normalise
- * @return mixed the normalised value
- */
- protected function normalise_value($column, $value) {
- $this->detect_objects($value);
- if (is_bool($value)) { // Always, convert boolean to int
- $value = (int)$value;
- } else if ($column->meta_type == 'B') { // CLOB detected, we return 'blob' array instead of raw value to allow
- if (!is_null($value)) { // binding/executing code later to know about its nature
- $value = array('blob' => $value);
- }
- } else if ($column->meta_type == 'X' && strlen($value) > 4000) { // CLOB detected (>4000 optimisation), we return 'clob'
- if (!is_null($value)) { // array instead of raw value to allow binding/
- $value = array('clob' => (string)$value); // executing code later to know about its nature
- }
- } else if ($value === '') {
- if ($column->meta_type == 'I' or $column->meta_type == 'F' or $column->meta_type == 'N') {
- $value = 0; // prevent '' problems in numeric fields
- }
- }
- return $value;
- }
- /**
- * Transforms the sql and params in order to emulate the LIMIT clause available in other DBs
- *
- * @param string $sql the SQL select query to execute.
- * @param array $params array of sql parameters
- * @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
- * @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
- * @return array with the transformed sql and params updated
- */
- private function get_limit_sql($sql, array $params = null, $limitfrom=0, $limitnum=0) {
- list($limitfrom, $limitnum) = $this->normalise_limit_from_num($limitfrom, $limitnum);
- // TODO: Add the /*+ FIRST_ROWS */ hint if there isn't another hint
- if ($limitfrom and $limitnum) {
- $sql = "SELECT oracle_o.*
- FROM (SELECT oracle_i.*, rownum AS oracle_rownum
- FROM ($sql) oracle_i
- WHERE rownum <= :oracle_num_rows
- ) oracle_o
- WHERE oracle_rownum > :oracle_skip_rows";
- $params['oracle_num_rows'] = $limitfrom + $limitnum;
- $params['oracle_skip_rows'] = $limitfrom;
- } else if ($limitfrom and !$limitnum) {
- $sql = "SELECT oracle_o.*
- FROM (SELECT oracle_i.*, rownum AS oracle_rownum
- FROM ($sql) oracle_i
- ) oracle_o
- WHERE oracle_rownum > :oracle_skip_rows";
- $params['oracle_skip_rows'] = $limitfrom;
- } else if (!$limitfrom and $limitnum) {
- $sql = "SELECT *
- FROM ($sql)
- WHERE rownum <= :oracle_num_rows";
- $params['oracle_num_rows'] = $limitnum;
- }
- return array($sql, $params);
- }
- /**
- * This function will handle all the column values before being inserted/updated to DB for Oracle
- * installations. This is because the "special feature" of Oracle where the empty string is
- * equal to NULL and this presents a problem with all our currently NOT NULL default '' fields.
- * (and with empties handling in general)
- *
- * Note that this function is 100% private and should be used, exclusively by DML functions
- * in this file. Also, this is considered a DIRTY HACK to be removed when possible.
- *
- * This function is private and must not be used outside this driver at all
- *
- * @param $table string the table where the record is going to be inserted/updated (without prefix)
- * @param $field string the field where the record is going to be inserted/updated
- * @param $value mixed the value to be inserted/updated
- */
- private function oracle_dirty_hack ($table, $field, $value) {
- // General bound parameter, just hack the spaces and pray it will work.
- if (!$table) {
- if ($value === '') {
- return ' ';
- } else if (is_bool($value)) {
- return (int)$value;
- } else {
- return $value;
- }
- }
- // Get metadata
- $columns = $this->get_columns($table);
- if (!isset($columns[$field])) {
- if ($value === '') {
- return ' ';
- } else if (is_bool($value)) {
- return (int)$value;
- } else {
- return $value;
- }
- }
- $column = $columns[$field];
- // !! This paragraph explains behaviour before Moodle 2.0:
- //
- // For Oracle DB, empty strings are converted to NULLs in DB
- // and this breaks a lot of NOT NULL columns currently Moodle. In the future it's
- // planned to move some of them to NULL, if they must accept empty values and this
- // piece of code will become less and less used. But, for now, we need it.
- // What we are going to do is to examine all the data being inserted and if it's
- // an empty string (NULL for Oracle) and the field is defined as NOT NULL, we'll modify
- // such data in the best form possible ("0" for booleans and numbers and " " for the
- // rest of strings. It isn't optimal, but the only way to do so.
- // In the opposite, when retrieving records from Oracle, we'll decode " " back to
- // empty strings to allow everything to work properly. DIRTY HACK.
- // !! These paragraphs explain the rationale about the change for Moodle 2.5:
- //
- // Before Moodle 2.0, we only used to apply this DIRTY HACK to NOT NULL columns, as
- // stated above, but it causes one problem in NULL columns where both empty strings
- // and real NULLs are stored as NULLs, being impossible to differentiate them when
- // being retrieved from DB.
- //
- // So, starting with Moodle 2.0, we are going to apply the DIRTY HACK to all the
- // CHAR/CLOB columns no matter of their nullability. That way, when retrieving
- // NULLABLE fields we'll get proper empties and NULLs differentiated, so we'll be able
- // to rely in NULL/empty/content contents without problems, until now that wasn't
- // possible at all.
- //
- // One space DIRTY HACK is now applied automatically for all query parameters
- // and results. The only problem is string concatenation where the glue must
- // be specified as "' '" sql fragment.
- //
- // !! Conclusions:
- //
- // From Moodle 2.5 onwards, ALL empty strings in Oracle DBs will be stored as
- // 1-whitespace char, ALL NULLs as NULLs and, obviously, content as content. And
- // those 1-whitespace chars will be converted back to empty strings by all the
- // get_field/record/set() functions transparently and any SQL needing direct handling
- // of empties will have to use placeholders or sql_isempty() helper function.
- // If the field isn't VARCHAR or CLOB, skip
- if ($column->meta_type != 'C' and $column->meta_type != 'X') {
- return $value;
- }
- // If the value isn't empty, skip
- if (!empty($value)) {
- return $value;
- }
- // Now, we have one empty value, going to be inserted to one VARCHAR2 or CLOB field
- // Try to get the best value to be inserted
- // The '0' string doesn't need any transformation, skip
- if ($value === '0') {
- return $value;
- }
- // Transformations start
- if (gettype($value) == 'boolean') {
- return '0'; // Transform false to '0' that evaluates the same for PHP
- } else if (gettype($value) == 'integer') {
- return '0'; // Transform 0 to '0' that evaluates the same for PHP
- } else if ($value === '') {
- return ' '; // Transform '' to ' ' that DON'T EVALUATE THE SAME
- // (we'll transform back again on get_records_XXX functions and others)!!
- }
- // Fail safe to original value
- return $value;
- }
- /**
- * Helper function to order by string length desc
- *
- * @param $a string first element to compare
- * @param $b string second element to compare
- * @return int < 0 $a goes first (is less), 0 $b goes first, 0 doesn't matter
- */
- private function compare_by_length_desc($a, $b) {
- return strlen($b) - strlen($a);
- }
- /**
- * Is db in unicode mode?
- * @return bool
- */
- public function setup_is_unicodedb() {
- $sql = "SELECT VALUE
- FROM NLS_DATABASE_PARAMETERS
- WHERE PARAMETER = 'NLS_CHARACTERSET'";
- $this->query_start($sql, null, SQL_QUERY_AUX);
- $stmt = $this->parse_query($sql);
- $result = oci_execute($stmt, $this->commit_status);
- $this->query_end($result, $stmt);
- $records = null;
- oci_fetch_all($stmt, $records, 0, -1, OCI_FETCHSTATEMENT_BY_COLUMN);
- oci_free_statement($stmt);
- return (isset($records['VALUE'][0]) and $records['VALUE'][0] === 'AL32UTF8');
- }
- /**
- * Do NOT use in code, to be used by database_manager only!
- * @param string|array $sql query
- * @return bool true
- * @throws ddl_change_structure_exception A DDL specific exception is thrown for any errors.
- */
- public function change_database_structure($sql) {
- $this->get_manager(); // Includes DDL exceptions classes ;-)
- $sqls = (array)$sql;
- try {
- foreach ($sqls as $sql) {
- $this->query_start($sql, null, SQL_QUERY_STRUCTURE);
- $stmt = $this->parse_query($sql);
- $result = oci_execute($stmt, $this->commit_status);
- $this->query_end($result, $stmt);
- oci_free_statement($stmt);
- }
- } catch (ddl_change_structure_exception $e) {
- $this->reset_caches();
- throw $e;
- }
- $this->reset_caches();
- return true;
- }
- protected function bind_params($stmt, array $params=null, $tablename=null) {
- $descriptors = array();
- if ($params) {
- $columns = array();
- if ($tablename) {
- $columns = $this->get_columns($tablename);
- }
- foreach($params as $key => $value) {
- // Decouple column name and param name as far as sometimes they aren't the same
- if ($key == 'o_newfieldtoset') { // found case where column and key diverge, handle that
- $columnname = key($value); // columnname is the key of the array
- $params[$key] = $value[$columnname]; // set the proper value in the $params array and
- $value = $value[$columnname]; // set the proper value in the $value variable
- } else {
- $columnname = preg_replace('/^o_/', '', $key); // Default columnname (for DB introspecting is key), but...
- }
- // Continue processing
- // Now, handle already detected LOBs
- if (is_array($value)) { // Let's go to bind special cases (lob descriptors)
- if (isset($value['clob'])) {
- $lob = oci_new_descriptor($this->oci, OCI_DTYPE_LOB);
- oci_bind_by_name($stmt, $key, $lob, -1, SQLT_CLOB);
- $lob->writeTemporary($this->oracle_dirty_hack($tablename, $columnname, $params[$key]['clob']), OCI_TEMP_CLOB);
- $descriptors[] = $lob;
- continue; // Column binding finished, go to next one
- } else if (isset($value['blob'])) {
- $lob = oci_new_descriptor($this->oci, OCI_DTYPE_LOB);
- oci_bind_by_name($stmt, $key, $lob, -1, SQLT_BLOB);
- $lob->writeTemporary($params[$key]['blob'], OCI_TEMP_BLOB);
- $descriptors[] = $lob;
- continue; // Column binding finished, go to next one
- }
- }
- // TODO: Put proper types and length is possible (enormous speedup)
- // Arrived here, continue with standard processing, using metadata if possible
- if (isset($columns[$columnname])) {
- $type = $columns[$columnname]->meta_type;
- $maxlength = $columns[$columnname]->max_length;
- } else {
- $type = '?';
- $maxlength = -1;
- }
- switch ($type) {
- case 'I':
- case 'R':
- // TODO: Optimise
- oci_bind_by_name($stmt, $key, $params[$key]);
- break;
- case 'N':
- case 'F':
- // TODO: Optimise
- oci_bind_by_name($stmt, $key, $params[$key]);
- break;
- case 'B':
- // TODO: Only arrive here if BLOB is null: Bind if so, else exception!
- // don't break here
- case 'X':
- // TODO: Only arrive here if CLOB is null or <= 4000 cc, else exception
- // don't break here
- default: // Bind as CHAR (applying dirty hack)
- // TODO: Optimise
- oci_bind_by_name($stmt, $key, $this->oracle_dirty_hack($tablename, $columnname, $params[$key]));
- }
- }
- }
- return $descriptors;
- }
- protected function free_descriptors($descriptors) {
- foreach ($descriptors as $descriptor) {
- oci_free_descriptor($descriptor);
- }
- }
- /**
- * This function is used to convert all the Oracle 1-space defaults to the empty string
- * like a really DIRTY HACK to allow it to work better until all those NOT NULL DEFAULT ''
- * fields will be out from Moodle.
- * @param string the string to be converted to '' (empty string) if it's ' ' (one space)
- * @param mixed the key of the array in case we are using this function from array_walk,
- * defaults to null for other (direct) uses
- * @return boolean always true (the converted variable is returned by reference)
- */
- public static function onespace2empty(&$item, $key=null) {
- $item = ($item === ' ') ? '' : $item;
- return true;
- }
- /**
- * Execute general sql query. Should be used only when no other method suitable.
- * Do NOT use this to make changes in db structure, use database_manager methods instead!
- * @param string $sql query
- * @param array $params query parameters
- * @return bool true
- * @throws dml_exception A DML specific exception is thrown for any errors.
- */
- public function execute($sql, array $params=null) {
- list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
- if (strpos($sql, ';') !== false) {
- throw new coding_exception('moodle_database::execute() Multiple sql statements found or bound parameters not used properly in query!');
- }
- list($sql, $params) = $this->tweak_param_names($sql, $params);
- $this->query_start($sql, $params, SQL_QUERY_UPDATE);
- $stmt = $this->parse_query($sql);
- $this->bind_params($stmt, $params);
- $result = oci_execute($stmt, $this->commit_status);
- $this->query_end($result, $stmt);
- oci_free_statement($stmt);
- return true;
- }
- /**
- * Get a single database record as an object using a SQL statement.
- *
- * The SQL statement should normally only return one record.
- * It is recommended to use get_records_sql() if more matches possible!
- *
- * @param string $sql The SQL string you wish to be executed, should normally only return one record.
- * @param array $params array of sql parameters
- * @param int $strictness IGNORE_MISSING means compatible mode, false returned if record not found, debug message if more found;
- * IGNORE_MULTIPLE means return first, ignore multiple records found(not recommended);
- * MUST_EXIST means throw exception if no record or multiple records found
- * @return mixed a fieldset object containing the first matching record, false or exception if error not found depending on mode
- * @throws dml_exception A DML specific exception is thrown for any errors.
- */
- public function get_record_sql($sql, array $params=null, $strictness=IGNORE_MISSING) {
- $strictness = (int)$strictness;
- if ($strictness == IGNORE_MULTIPLE) {
- // do not limit here - ORA does not like that
- $rs = $this->get_recordset_sql($sql, $params);
- $result = false;
- foreach ($rs as $rec) {
- $result = $rec;
- break;
- }
- $rs->close();
- return $result;
- }
- return parent::get_record_sql($sql, $params, $strictness);
- }
- /**
- * Get a number of records as a moodle_recordset using a SQL statement.
- *
- * Since this method is a little less readable, use of it should be restricted to
- * code where it's possible there might be large datasets being returned. For known
- * small datasets use get_records_sql - it leads to simpler code.
- *
- * The return type is like:
- * @see function get_recordset.
- *
- * @param string $sql the SQL select query to execute.
- * @param array $params array of sql parameters
- * @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
- * @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
- * @return moodle_recordset instance
- * @throws dml_exception A DML specific exception is thrown for any errors.
- */
- public function get_recordset_sql($sql, array $params=null, $limitfrom=0, $limitnum=0) {
- list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
- list($rawsql, $params) = $this->get_limit_sql($sql, $params, $limitfrom, $limitnum);
- list($rawsql, $params) = $this->tweak_param_names($rawsql, $params);
- $this->query_start($rawsql, $params, SQL_QUERY_SELECT);
- $stmt = $this->parse_query($rawsql);
- $this->bind_params($stmt, $params);
- $result = oci_execute($stmt, $this->commit_status);
- $this->query_end($result, $stmt);
- return $this->create_recordset($stmt);
- }
- protected function create_recordset($stmt) {
- return new oci_native_moodle_recordset($stmt);
- }
- /**
- * Get a number of records as an array of objects using a SQL statement.
- *
- * Return value is like:
- * @see function get_records.
- *
- * @param string $sql the SQL select query to execute. The first column of this SELECT statement
- * must be a unique value (usually the 'id' field), as it will be used as the key of the
- * returned array.
- * @param array $params array of sql parameters
- * @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
- * @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
- * @return array of objects, or empty array if no records were found
- * @throws dml_exception A DML specific exception is thrown for any errors.
- */
- public function get_records_sql($sql, array $params=null, $limitfrom=0, $limitnum=0) {
- list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
- list($rawsql, $params) = $this->get_limit_sql($sql, $params, $limitfrom, $limitnum);
- list($rawsql, $params) = $this->tweak_param_names($rawsql, $params);
- $this->query_start($rawsql, $params, SQL_QUERY_SELECT);
- $stmt = $this->parse_query($rawsql);
- $this->bind_params($stmt, $params);
- $result = oci_execute($stmt, $this->commit_status);
- $this->query_end($result, $stmt);
- $records = null;
- oci_fetch_all($stmt, $records, 0, -1, OCI_FETCHSTATEMENT_BY_ROW);
- oci_free_statement($stmt);
- $return = array();
- foreach ($records as $row) {
- $row = array_change_key_case($row, CASE_LOWER);
- unset($row['oracle_rownum']);
- array_walk($row, array('oci_native_moodle_database', 'onespace2empty'));
- $id = reset($row);
- if (isset($return[$id])) {
- $colname = key($row);
- debugging("Did you remember to make the first column something unique in your call to get_records? Duplicate value '$id' found in column '$colname'.", DEBUG_DEVELOPER);
- }
- $return[$id] = (object)$row;
- }
- return $return;
- }
- /**
- * Selects records and return values (first field) as an array using a SQL statement.
- *
- * @param string $sql The SQL query
- * @param array $params array of sql parameters
- * @return array of values
- * @throws dml_exception A DML specific exception is thrown for any errors.
- */
- public function get_fieldset_sql($sql, array $params=null) {
- list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
- list($sql, $params) = $this->tweak_param_names($sql, $params);
- $this->query_start($sql, $params, SQL_QUERY_SELECT);
- $stmt = $this->parse_query($sql);
- $this->bind_params($stmt, $params);
- $result = oci_execute($stmt, $this->commit_status);
- $this->query_end($result, $stmt);
- $records = null;
- oci_fetch_all($stmt, $records, 0, -1, OCI_FETCHSTATEMENT_BY_COLUMN);
- oci_free_statement($stmt);
- $return = reset($records);
- array_walk($return, array('oci_native_moodle_database', 'onespace2empty'));
- return $return;
- }
- /**
- * Insert new record into database, as fast as possible, no safety checks, lobs not supported.
- * @param string $table name
- * @param mixed $params data record as object or array
- * @param bool $returnit return it of inserted record
- * @param bool $bulk true means repeated inserts e…
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