--- /dev/null
+<?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 mssql class representing moodle database interface.
+ *
+ * @package moodlecore
+ * @subpackage DML
+ * @copyright 2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+require_once($CFG->libdir.'/dml/moodle_database.php');
+require_once($CFG->libdir.'/dml/mssql_native_moodle_recordset.php');
+require_once($CFG->libdir.'/dml/mssql_native_moodle_temptables.php');
+
+/**
+ * Native mssql class representing moodle database interface.
+ */
+class mssql_native_moodle_database extends moodle_database {
+
+ protected $mssql = null;
+ private $temptables; // Control existing temptables (mssql_moodle_temptables object)
+
+ /**
+ * 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 (!function_exists('mssql_connect')) {
+ return get_string('mssqlextensionisnotpresentinphp', '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 'mssql';
+ }
+
+ /**
+ * Returns more specific database driver type
+ * Note: can be used before connect()
+ * @return string db type mysql, pgsql, postgres7
+ */
+ protected function get_dbtype() {
+ return 'mssql';
+ }
+
+ /**
+ * Returns general database library name
+ * Note: can be used before connect()
+ * @return string db type adodb, 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('nativemssql', 'install');
+ }
+
+ /**
+ * Returns sql generator used for db manipulation.
+ * Used mostly in upgrade.php scripts. mssql overrides it
+ * in order to share the mssql_moodle_temptables
+ * between the driver and the generator
+ *
+ * @return object database_manager instance
+ */
+ public function get_manager() {
+ global $CFG;
+
+ if (!$this->database_manager) {
+ require_once($CFG->libdir.'/ddllib.php');
+
+ $classname = $this->get_dbfamily().'_sql_generator';
+ require_once("$CFG->libdir/ddl/$classname.php");
+ $generator = new $classname($this, $this->temptables);
+
+ $this->database_manager = new database_manager($this, $generator);
+ }
+ return $this->database_manager;
+ }
+
+ /**
+ * Returns localised database configuration help.
+ * Note: can be used before connect()
+ * @return string
+ */
+ public function get_configuration_help() {
+ return get_string('nativemssqlhelp', 'install');
+ }
+
+ /**
+ * Returns localised database description
+ * Note: can be used before connect()
+ * @return string
+ */
+ public function get_configuration_hints() {
+ $str = get_string('databasesettingssub_mssql', 'install');
+ $str .= "<p style='text-align:right'><a href=\"javascript:void(0)\" ";
+ $str .= "onclick=\"return window.open('http://docs.moodle.org/en/Installing_MSSQL_for_PHP')\"";
+ $str .= ">";
+ $str .= '<img src="pix/docs.gif' . '" alt="Docs" class="iconhelp" />';
+ $str .= get_string('moodledocslink', 'install') . '</a></p>';
+ return $str;
+ }
+
+ /**
+ * Connect to db
+ * Must be called before other methods.
+ * @param string $dbhost
+ * @param string $dbuser
+ * @param string $dbpass
+ * @param string $dbname
+ * @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());
+ }
+
+ $driverstatus = $this->driver_installed();
+
+ if ($driverstatus !== true) {
+ throw new dml_exception('dbdriverproblem', $driverstatus);
+ }
+
+ $this->store_settings($dbhost, $dbuser, $dbpass, $dbname, $prefix, $dboptions);
+
+ ob_start();
+ if (!empty($this->dboptions['dbpersit'])) { // persistent connection
+ $this->mssql = mssql_pconnect($this->dbhost, $this->dbuser, $this->dbpass, true);
+ } else {
+ $this->mssql = mssql_connect($this->dbhost, $this->dbuser, $this->dbpass, true);
+ }
+ $dberr = ob_get_contents();
+ ob_end_clean();
+
+ if ($this->mssql === false) {
+ $this->mssql = null;
+ throw new dml_connection_exception($dberr);
+ }
+
+ // already connected, select database and set some env. variables
+ $this->query_start("--mssql_select_db", null, SQL_QUERY_AUX);
+ $result = mssql_select_db($this->dbname, $this->mssql);
+ $this->query_end($result);
+
+ // No need to set charset. It's UTF8, with transparent conversions
+ // back and forth performed both by FreeTDS or ODBTP
+
+ // Allow quoted identifiers
+ $sql = "SET QUOTED_IDENTIFIER ON";
+ $this->query_start($sql, null, SQL_QUERY_AUX);
+ $result = mssql_query($sql, $this->mssql);
+ $this->query_end($result);
+
+ $this->free_result($result);
+
+ // Force ANSI nulls so the NULL check was done by IS NULL and NOT IS NULL
+ // instead of equal(=) and distinct(<>) simbols
+ $sql = "SET ANSI_NULLS ON";
+ $this->query_start($sql, null, SQL_QUERY_AUX);
+ $result = mssql_query($sql, $this->mssql);
+ $this->query_end($result);
+
+ $this->free_result($result);
+
+ // Force ANSI warnings so arithmetic/string overflows will be
+ // returning error instead of transparently truncating data
+ $sql = "SET ANSI_WARNINGS ON";
+ $this->query_start($sql, null, SQL_QUERY_AUX);
+ $result = mssql_query($sql, $this->mssql);
+ $this->query_end($result);
+
+ // Concatenating null with anything MUST return NULL
+ $sql = "SET CONCAT_NULL_YIELDS_NULL ON";
+ $this->query_start($sql, null, SQL_QUERY_AUX);
+ $result = mssql_query($sql, $this->mssql);
+ $this->query_end($result);
+
+ $this->free_result($result);
+
+ // Set transactions isolation level to READ_COMMITTED
+ // prevents dirty reads when using transactions +
+ // is the default isolation level of MSSQL
+ $sql = "SET TRANSACTION ISOLATION LEVEL READ COMMITTED";
+ $this->query_start($sql, NULL, SQL_QUERY_AUX);
+ $result = mssql_query($sql, $this->mssql);
+ $this->query_end($result);
+
+ $this->free_result($result);
+
+ // Connection stabilished and configured, going to instantiate the temptables controller
+ $this->temptables = new mssql_native_moodle_temptables($this);
+
+ 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 clossing conn
+ if ($this->mssql) {
+ mssql_close($this->mssql);
+ $this->mssql = 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, $extrainfo);
+ }
+
+ /**
+ * Called immediately after each db query.
+ * @param mixed db specific result
+ * @return void
+ */
+ protected function query_end($result) {
+ parent::query_end($result);
+ }
+
+ /**
+ * Returns database server info array
+ * @return array
+ */
+ public function get_server_info() {
+ static $info;
+ if (!$info) {
+ $info = array();
+ $sql = 'sp_server_info 2';
+ $this->query_start($sql, null, SQL_QUERY_AUX);
+ $result = mssql_query($sql, $this->mssql);
+ $this->query_end($result);
+ $row = mssql_fetch_row($result);
+ $info['server'] = $row[2];
+ $this->free_result($result);
+
+ $sql = 'sp_server_info 500';
+ $this->query_start($sql, null, SQL_QUERY_AUX);
+ $result = mssql_query($sql, $this->mssql);
+ $this->query_end($result);
+ $row = mssql_fetch_row($result);
+ $info['version'] = $row[2];
+ $this->free_result($result);
+ }
+ return $info;
+ }
+
+ protected function is_min_version($version) {
+ $server = $this->get_server_info();
+ $server = $server['version'];
+ return version_compare($server, $version, '>=');
+ }
+
+ /**
+ * Converts short table name {tablename} to real table name
+ * supporting temp tables (#) if detected
+ *
+ * @param string sql
+ * @return string sql
+ */
+ protected function fix_table_names($sql) {
+ if (preg_match_all('/\{([a-z][a-z0-9_]*)\}/', $sql, $matches)) {
+ foreach($matches[0] as $key=>$match) {
+ $name = $matches[1][$key];
+ $sql = str_replace($match, $this->temptables->get_correct_name($name), $sql);
+ }
+ }
+ return $sql;
+ }
+
+ /**
+ * Returns supported query parameter types
+ * @return bitmask
+ */
+ protected function allowed_param_types() {
+ return SQL_PARAMS_QM; // Not really, but emulated, see emulate_bound_params()
+ }
+
+ /**
+ * Returns last error reported by database engine.
+ */
+ public function get_last_error() {
+ return mssql_get_last_message();
+ }
+
+ /**
+ * Return tables in database WITHOUT current prefix
+ * @return array of table names in lowercase and without prefix
+ */
+ public function get_tables($usecache=true) {
+ if ($usecache and $this->tables !== null) {
+ return $this->tables;
+ }
+ $this->tables = array();
+ $sql = "SELECT table_name
+ FROM information_schema.tables
+ WHERE table_name LIKE '$this->prefix%'
+ AND table_type = 'BASE TABLE'";
+ $this->query_start($sql, null, SQL_QUERY_AUX);
+ $result = mssql_query($sql, $this->mssql);
+ $this->query_end($result);
+
+ if ($result) {
+ while ($row = mssql_fetch_row($result)) {
+ $tablename = reset($row);
+ if (strpos($tablename, $this->prefix) !== 0) {
+ continue;
+ }
+ $tablename = substr($tablename, strlen($this->prefix));
+ $this->tables[$tablename] = $tablename;
+ }
+ $this->free_result($result);
+ }
+
+ // Add the currently available temptables
+ $this->tables = array_merge($this->tables, $this->temptables->get_temptables());
+ return $this->tables;
+ }
+
+ /**
+ * Return table indexes - everything lowercased
+ * @return array of arrays
+ */
+ public function get_indexes($table) {
+ $indexes = array();
+ $tablename = $this->prefix.$table;
+
+ // Indexes aren't covered by information_schema metatables, so we need to
+ // go to sys ones. Skipping primary key indexes on purpose.
+ $sql = "SELECT i.name AS index_name, i.is_unique, ic.index_column_id, c.name AS column_name
+ FROM sys.indexes i
+ JOIN sys.index_columns ic ON i.object_id = ic.object_id AND i.index_id = ic.index_id
+ JOIN sys.columns c ON ic.object_id = c.object_id AND ic.column_id = c.column_id
+ JOIN sys.tables t ON i.object_id = t.object_id
+ WHERE t.name = '$tablename'
+ AND i.is_primary_key = 0
+ ORDER BY i.name, i.index_id, ic.index_column_id";
+
+ $this->query_start($sql, null, SQL_QUERY_AUX);
+ $result = mssql_query($sql, $this->mssql);
+ $this->query_end($result);
+
+ if ($result) {
+ $lastindex = '';
+ $unique = false;
+ $columns = array();
+ while ($row = mssql_fetch_assoc($result)) {
+ if ($lastindex and $lastindex != $row['index_name']) { // Save lastindex to $indexes and reset info
+ $indexes[$lastindex] = array('unique' => $unique, 'columns' => $columns);
+ $unique = false;
+ $columns = array();
+ }
+ $lastindex = $row['index_name'];
+ $unique = empty($row['is_unique']) ? false : true;
+ $columns[] = $row['column_name'];
+ }
+ if ($lastindex ) { // Add the last one if exists
+ $indexes[$lastindex] = array('unique' => $unique, 'columns' => $columns);
+ }
+ $this->free_result($result);
+ }
+ return $indexes;
+ }
+
+ /**
+ * Returns datailed 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 and isset($this->columns[$table])) {
+ return $this->columns[$table];
+ }
+
+ $this->columns[$table] = array();
+
+ $tablename = $this->temptables->get_correct_name($table);
+
+ if (!$this->temptables->is_temptable($table)) { // normal table, get metadata from own schema
+ $sql = "SELECT column_name AS name,
+ data_type AS type,
+ numeric_precision AS max_length,
+ character_maximum_length AS char_max_length,
+ numeric_scale AS scale,
+ is_nullable AS is_nullable,
+ columnproperty(object_id(quotename(table_schema) + '.' +
+ quotename(table_name)), column_name, 'IsIdentity') AS auto_increment,
+ column_default AS default_value
+ FROM information_schema.columns
+ WHERE table_name = '$tablename'
+ ORDER BY ordinal_position";
+ } else { // temp table, get metadata from tempdb schema
+ $sql = "SELECT column_name AS name,
+ data_type AS type,
+ numeric_precision AS max_length,
+ character_maximum_length AS char_max_length,
+ numeric_scale AS scale,
+ is_nullable AS is_nullable,
+ columnproperty(object_id(quotename(table_schema) + '.' +
+ quotename(table_name)), column_name, 'IsIdentity') AS auto_increment,
+ column_default AS default_value
+ FROM tempdb.information_schema.columns
+ WHERE table_name like '{$tablename}__________%'
+ ORDER BY ordinal_position";
+ }
+
+ $this->query_start($sql, null, SQL_QUERY_AUX);
+ $result = mssql_query($sql, $this->mssql);
+ $this->query_end($result);
+
+ if (!$result) {
+ return array();
+ }
+
+ while ($rawcolumn = mssql_fetch_assoc($result)) {
+
+ $rawcolumn = (object)$rawcolumn;
+
+ $info = new object();
+ $info->name = $rawcolumn->name;
+ $info->type = $rawcolumn->type;
+ $info->meta_type = $this->mssqltype2moodletype($info->type);
+
+ // Prepare auto_increment info
+ $info->auto_increment = $rawcolumn->auto_increment ? true : false;
+
+ // Define type for auto_increment columns
+ $info->meta_type = ($info->auto_increment && $info->meta_type == 'I') ? 'R' : $info->meta_type;
+
+ // id columns being auto_incremnt are PK by definition
+ $info->primary_key = ($info->name == 'id' && $info->meta_type == 'R' && $info->auto_increment);
+
+ // Put correct length for character and LOB types
+ $info->max_length = $info->meta_type == 'C' ? $rawcolumn->char_max_length : $rawcolumn->max_length;
+ $info->max_length = ($info->meta_type == 'X' || $info->meta_type == 'B') ? -1 : $info->max_length;
+
+ // Scale
+ $info->scale = $rawcolumn->scale ? $rawcolumn->scale : false;
+
+ // Prepare not_null info
+ $info->not_null = $rawcolumn->is_nullable == 'NO' ? true : false;
+
+ // Process defaults
+ $info->has_default = !empty($rawcolumn->default_value);
+ $info->default_value = preg_replace("/^[\(N]+[']?(.*?)[']?[\)]+$/", '\\1', $rawcolumn->default_value);
+
+ // Process binary
+ $info->binary = $info->meta_type == 'B' ? true : false;
+
+ $this->columns[$table][$info->name] = new database_column_info($info);
+ }
+ $this->free_result($result);
+
+ return $this->columns[$table];
+ }
+
+ /**
+ * 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 $value value we are going to normalise
+ * @return mixed the normalised value
+ */
+ private function normalise_value($column, $value) {
+ if (is_bool($value)) { /// Always, convert boolean to int
+ $value = (int)$value;
+
+ } else if ($column->meta_type == 'B') { // BLOBs need to be properly "packed", but can be inserted directly if so.
+ if (!is_null($value)) { // If value not null, unpack it to unquoted hexadecimal byte-string format
+ $value = unpack('H*hex', $value); // we leave it as array, so emulate_bound_params() can detect it
+ } // easily and "bind" the param ok.
+
+ } else if ($column->meta_type == 'X') { // MSSQL doesn't cast from int to text, so if text column
+ if (is_numeric($value)) { // and is numeric value then cast to string
+ $value = array('numstr' => (string)$value); // and put into array, so emulate_bound_params() will know how
+ } // to "bind" the param ok, avoiding reverse conversion to number
+
+ } 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;
+ }
+
+ /**
+ * Selectively call mssql_free_result(), avoiding some warnings without using the horrible @
+ *
+ * @param mssql_resource $resource resource to be freed if possible
+ */
+ private function free_result($resource) {
+ if (!is_bool($resource)) { // true/false resources cannot be freed
+ mssql_free_result($resource);
+ }
+ }
+
+ /**
+ * Provides mapping between mssql native data types and moodle_database - database_column_info - ones)
+ *
+ * @param string $mssql_type native mssql data type
+ * @return string 1-char database_column_info data type
+ */
+ private function mssqltype2moodletype($mssql_type) {
+ $type = null;
+ switch (strtoupper($mssql_type)) {
+ case 'BIT':
+ $type = 'L';
+ break;
+ case 'INT':
+ case 'SMALLINT':
+ case 'INTEGER':
+ case 'BIGINT':
+ $type = 'I';
+ break;
+ case 'DECIMAL':
+ case 'REAL':
+ case 'FLOAT':
+ $type = 'N';
+ break;
+ case 'VARCHAR':
+ case 'NVARCHAR':
+ $type = 'C';
+ break;
+ case 'TEXT':
+ case 'NTEXT':
+ case 'VARCHAR(MAX)':
+ case 'NVARCHAR(MAX)':
+ $type = 'X';
+ break;
+ case 'IMAGE':
+ case 'VARBINARY(MAX)':
+ $type = 'B';
+ break;
+ case 'DATETIME':
+ $type = 'D';
+ break;
+ }
+ if (!$type) {
+ throw new dml_exception('invalidmssqlnativetype', $mssql_type);
+ }
+ return $type;
+ }
+
+ /**
+ * Do NOT use in code, to be used by database_manager only!
+ * @param string $sql query
+ * @return bool true
+ * @throws dml_exception if error
+ */
+ public function change_database_structure($sql) {
+ $this->reset_caches();
+
+ $this->query_start($sql, null, SQL_QUERY_STRUCTURE);
+ $result = @mssql_query($sql, $this->mssql);
+ $this->query_end($result);
+
+ return true;
+ }
+
+ /**
+ * Very ugly hack which emulates bound parameters in queries
+ * because the mssql driver doesn't support placeholders natively at all
+ */
+ protected function emulate_bound_params($sql, array $params=null) {
+ if (empty($params)) {
+ return $sql;
+ }
+ /// ok, we have verified sql statement with ? and correct number of params
+ $return = strtok($sql, '?');
+ foreach ($params as $param) {
+ if (is_bool($param)) {
+ $return .= (int)$param;
+
+ } else if (is_array($param) && isset($param['hex'])) { // detect hex binary, bind it specially
+ $return .= '0x' . $param['hex'];
+
+ } else if (is_array($param) && isset($param['numstr'])) { // detect numerical strings that *must not*
+ $return .= "N'{$param['numstr']}'"; // be converted back to number params, but bound as strings
+
+ } else if (is_null($param)) {
+ $return .= 'NULL';
+
+ } else if (is_number($param)) { // we can not use is_numeric() because it eats leading zeros from strings like 0045646
+ $return .= $param;
+
+ } else if (is_float($param)) {
+ $return .= $param;
+
+ } else {
+ $param = str_replace("'", "''", $param);
+ $return .= "N'$param'";
+ }
+
+ $return .= strtok('?');
+ }
+ return $return;
+ }
+
+ /**
+ * 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::execute_sql() instead!
+ * @param string $sql query
+ * @param array $params query parameters
+ * @return bool true
+ * @throws dml_exception if error
+ */
+ public function execute($sql, array $params=null) {
+
+ list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
+ $rawsql = $this->emulate_bound_params($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!');
+ }
+
+ $this->query_start($sql, $params, SQL_QUERY_UPDATE);
+ $result = @mssql_query($rawsql, $this->mssql);
+ $this->query_end($result);
+ $this->free_result($result);
+
+ return true;
+ }
+
+ /**
+ * 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 as for @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 $limitfrom is set).
+ * @return mixed an moodle_recordset object
+ * @throws dml_exception if error
+ */
+ public function get_recordset_sql($sql, array $params=null, $limitfrom=0, $limitnum=0) {
+ $limitfrom = (int)$limitfrom;
+ $limitnum = (int)$limitnum;
+ $limitfrom = ($limitfrom < 0) ? 0 : $limitfrom;
+ $limitnum = ($limitnum < 0) ? 0 : $limitnum;
+ if ($limitfrom or $limitnum) {
+ if ($limitnum < 1) {
+ $limitnum = "18446744073709551615";
+ }
+ $fetch = $limitfrom + $limitnum;
+ $sql = preg_replace('/^([\s(])*SELECT( DISTINCT)?(?!\s*TOP\s*\()/i',
+ "\\1SELECT\\2 TOP $fetch", $sql);
+ }
+
+ list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
+ $rawsql = $this->emulate_bound_params($sql, $params);
+
+ $this->query_start($sql, $params, SQL_QUERY_SELECT);
+ $result = @mssql_query($rawsql, $this->mssql);
+ $this->query_end($result);
+
+ if ($limitfrom) {
+ @mssql_data_seek($result, $limitfrom);
+ }
+
+ return $this->create_recordset($result);
+ }
+
+ protected function create_recordset($result) {
+ return new mssql_native_moodle_recordset($result);
+ }
+
+ /**
+ * Get a number of records as an array of objects using a SQL statement.
+ *
+ * Return value as for @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 $limitfrom is set).
+ * @return mixed an array of objects, or empty array if no records were found
+ * @throws dml_exception if error
+ */
+ public function get_records_sql($sql, array $params=null, $limitfrom=0, $limitnum=0) {
+
+ $rs = $this->get_recordset_sql($sql, $params, $limitfrom, $limitnum);
+
+ $results = array();
+
+ foreach ($rs as $row) {
+ $id = reset($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);
+ }
+ $results[$id] = (object)$row;
+ }
+ $rs->close();
+
+ return $results;
+ }
+
+ /**
+ * Selects records and return values (first field) as an array using a SQL statement.
+ *
+ * @param string $sql The SQL query
+ * @param array $params array of sql parameters
+ * @return mixed array of values
+ * @throws dml_exception if error
+ */
+ public function get_fieldset_sql($sql, array $params=null) {
+
+ $rs = $this->get_recordset_sql($sql, $params);
+
+ $results = array();
+
+ foreach ($rs as $row) {
+ $results[] = reset($row);
+ }
+ $rs->close();
+
+ return $results;
+ }
+
+ /**
+ * 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 expected
+ * @param bool $customsequence true if 'id' included in $params, disables $returnid
+ * @return true or new id
+ * @throws dml_exception if error
+ */
+ public function insert_record_raw($table, $params, $returnid=true, $bulk=false, $customsequence=false) {
+ if (!is_array($params)) {
+ $params = (array)$params;
+ }
+
+ $returning = "";
+
+ if ($customsequence) {
+ if (!isset($params['id'])) {
+ throw new coding_exception('moodle_database::insert_record_raw() id field must be specified if custom sequences used.');
+ }
+ $returnid = false;
+ } else {
+ unset($params['id']);
+ if ($returnid) {
+ $returning = "; SELECT SCOPE_IDENTITY()";
+ }
+ }
+
+ if (empty($params)) {
+ throw new coding_exception('moodle_database::insert_record_raw() no fields found.');
+ }
+
+ $fields = implode(',', array_keys($params));
+ $qms = array_fill(0, count($params), '?');
+ $qms = implode(',', $qms);
+
+ $sql = "INSERT INTO {" . $table . "} ($fields) VALUES($qms) $returning";
+
+ list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
+ $rawsql = $this->emulate_bound_params($sql, $params);
+
+ $this->query_start($sql, $params, SQL_QUERY_INSERT);
+ $result = @mssql_query($rawsql, $this->mssql);
+ $this->query_end($result);
+
+ if ($returning !== "") {
+ $row = mssql_fetch_assoc($result);
+ $params['id'] = reset($row);
+ }
+ $this->free_result($result);
+
+ if (!$returnid) {
+ return true;
+ }
+
+ return (int)$params['id'];
+ }
+
+ /**
+ * Insert a record into a table and return the "id" field if required.
+ *
+ * Some conversions and safety checks are carried out. Lobs are supported.
+ * If the return ID isn't required, then this just reports success as true/false.
+ * $data is an object containing needed data
+ * @param string $table The database table to be inserted into
+ * @param object $data A data object with values for one or more fields in the record
+ * @param bool $returnid Should the id of the newly created record entry be returned? If this option is not requested then true/false is returned.
+ * @return true or new id
+ * @throws dml_exception if error
+ */
+ public function insert_record($table, $dataobject, $returnid=true, $bulk=false) {
+ if (!is_object($dataobject)) {
+ $dataobject = (object)$dataobject;
+ }
+
+ unset($dataobject->id);
+
+ $columns = $this->get_columns($table);
+ $cleaned = array();
+
+ foreach ($dataobject as $field => $value) {
+ if (!isset($columns[$field])) {
+ continue;
+ }
+ $column = $columns[$field];
+ $cleaned[$field] = $this->normalise_value($column, $value);
+ }
+
+ return $this->insert_record_raw($table, $cleaned, $returnid, $bulk);
+ }
+
+ /**
+ * Import a record into a table, id field is required.
+ * Safety checks are NOT carried out. Lobs are supported.
+ *
+ * @param string $table name of database table to be inserted into
+ * @param object $dataobject A data object with values for one or more fields in the record
+ * @return bool true
+ * @throws dml_exception if error
+ */
+ public function import_record($table, $dataobject) {
+ $dataobject = (object)$dataobject;
+
+ $columns = $this->get_columns($table);
+ $cleaned = array();
+
+ foreach ($dataobject as $field=>$value) {
+ if (!isset($columns[$field])) {
+ continue;
+ }
+ $cleaned[$field] = $value;
+ }
+
+ return $this->insert_record_raw($table, $cleaned, false, true, true);
+ }
+
+ /**
+ * Update record in database, as fast as possible, no safety checks, lobs not supported.
+ * @param string $table name
+ * @param mixed $params data record as object or array
+ * @param bool true means repeated updates expected
+ * @return bool true
+ * @throws dml_exception if error
+ */
+ public function update_record_raw($table, $params, $bulk=false) {
+ if (!is_array($params)) {
+ $params = (array)$params;
+ }
+ if (!isset($params['id'])) {
+ throw new coding_exception('moodle_database::update_record_raw() id field must be specified.');
+ }
+ $id = $params['id'];
+ unset($params['id']);
+
+ if (empty($params)) {
+ throw new coding_exception('moodle_database::update_record_raw() no fields found.');
+ }
+
+ $sets = array();
+ foreach ($params as $field=>$value) {
+ $sets[] = "$field = ?";
+ }
+
+ $params[] = $id; // last ? in WHERE condition
+
+ $sets = implode(',', $sets);
+ $sql = "UPDATE {" . $table . "} SET $sets WHERE id = ?";
+
+ list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
+ $rawsql = $this->emulate_bound_params($sql, $params);
+
+ $this->query_start($sql, $params, SQL_QUERY_UPDATE);
+ $result = @mssql_query($rawsql, $this->mssql);
+ $this->query_end($result);
+
+ $this->free_result($result);
+ return true;
+ }
+
+ /**
+ * Update a record in a table
+ *
+ * $dataobject is an object containing needed data
+ * Relies on $dataobject having a variable "id" to
+ * specify the record to update
+ *
+ * @param string $table The database table to be checked against.
+ * @param object $dataobject An object with contents equal to fieldname=>fieldvalue. Must have an entry for 'id' to map to the table specified.
+ * @param bool true means repeated updates expected
+ * @return bool true
+ * @throws dml_exception if error
+ */
+ public function update_record($table, $dataobject, $bulk=false) {
+ if (!is_object($dataobject)) {
+ $dataobject = (object)$dataobject;
+ }
+
+ $columns = $this->get_columns($table);
+ $cleaned = array();
+
+ foreach ($dataobject as $field => $value) {
+ if (!isset($columns[$field])) {
+ continue;
+ }
+ $column = $columns[$field];
+ $cleaned[$field] = $this->normalise_value($column, $value);
+ }
+
+ return $this->update_record_raw($table, $cleaned, $bulk);
+ }
+
+ /**
+ * Set a single field in every table record which match a particular WHERE clause.
+ *
+ * @param string $table The database table to be checked against.
+ * @param string $newfield the field to set.
+ * @param string $newvalue the value to set the field to.
+ * @param string $select A fragment of SQL to be used in a where clause in the SQL call.
+ * @param array $params array of sql parameters
+ * @return bool true
+ * @throws dml_exception if error
+ */
+ public function set_field_select($table, $newfield, $newvalue, $select, array $params=null) {
+
+ if ($select) {
+ $select = "WHERE $select";
+ }
+ if (is_null($params)) {
+ $params = array();
+ }
+
+ /// Get column metadata
+ $columns = $this->get_columns($table);
+ $column = $columns[$newfield];
+
+ $newvalue = $this->normalise_value($column, $newvalue);
+
+ if (is_null($newvalue)) {
+ $newfield = "$newfield = NULL";
+ } else {
+ $newfield = "$newfield = ?";
+ array_unshift($params, $newvalue);
+ }
+ $sql = "UPDATE {" . $table . "} SET $newfield $select";
+
+ list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
+ $rawsql = $this->emulate_bound_params($sql, $params);
+
+ $this->query_start($sql, $params, SQL_QUERY_UPDATE);
+ $result = @mssql_query($rawsql, $this->mssql);
+ $this->query_end($result);
+
+ $this->free_result($result);
+
+ return true;
+ }
+
+ /**
+ * Delete one or more records from a table which match a particular WHERE clause.
+ *
+ * @param string $table The database table to be checked against.
+ * @param string $select A fragment of SQL to be used in a where clause in the SQL call (used to define the selection criteria).
+ * @param array $params array of sql parameters
+ * @return bool true
+ * @throws dml_exception if error
+ */
+ public function delete_records_select($table, $select, array $params=null) {
+
+ if ($select) {
+ $select = "WHERE $select";
+ }
+
+ $sql = "DELETE FROM {" . $table . "} $select";
+
+ list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
+ $rawsql = $this->emulate_bound_params($sql, $params);
+
+ $this->query_start($sql, $params, SQL_QUERY_UPDATE);
+ $result = @mssql_query($rawsql, $this->mssql);
+ $this->query_end($result);
+
+ $this->free_result($result);
+
+ return true;
+ }
+
+/// SQL helper functions
+
+ public function sql_bitxor($int1, $int2) {
+ return '(' . $this->sql_bitor($int1, $int2) . ' - ' . $this->sql_bitand($int1, $int2) . ')';
+ }
+
+ public function sql_cast_char2int($fieldname, $text=false) {
+ return ' CAST(' . $fieldname . ' AS INT) ';
+ }
+
+ public function sql_ceil($fieldname) {
+ return ' CEILING(' . $fieldname . ')';
+ }
+
+ public function sql_concat() {
+ $arr = func_get_args();
+ foreach ($arr as $key => $ele) {
+ $arr[$key] = ' CAST(' . $ele . ' AS VARCHAR(255)) ';
+ }
+ $s = implode(' + ', $arr);
+ if ($s === '') {
+ return " '' ";
+ }
+ return " $s ";
+ }
+
+ public function sql_concat_join($separator="' '", $elements=array()) {
+ for ($n=count($elements)-1; $n > 0 ; $n--) {
+ array_splice($elements, $n, 0, $separator);
+ }
+ $s = implode(' + ', $elements);
+ if ($s === '') {
+ return " '' ";
+ }
+ return " $s ";
+ }
+
+ public function sql_isempty($tablename, $fieldname, $nullablefield, $textfield) {
+ if ($textfield) {
+ return $this->sql_compare_text($fieldname)." = '' ";
+ } else {
+ return " $fieldname = '' ";
+ }
+ }
+
+ /**
+ * Returns the SQL text to be used to calculate the length in characters of one expression.
+ * @param string fieldname or expression to calculate its length in characters.
+ * @return string the piece of SQL code to be used in the statement.
+ */
+ public function sql_length($fieldname) {
+ return ' LEN(' . $fieldname . ')';
+ }
+
+ public function sql_order_by_text($fieldname, $numchars=32) {
+ return ' CONVERT(varchar, ' . $fieldname . ', ' . $numchars . ')';
+ }
+
+ /**
+ * Returns the SQL for returning searching one string for the location of another.
+ */
+ public function sql_position($needle, $haystack) {
+ return "CHARINDEX(($needle), ($haystack))";
+ }
+
+ /**
+ * Returns the proper substr() function for each DB.
+ * NOTE: this was originally returning only function name
+ *
+ * @param string $expr some string field, no aggregates
+ * @param mixed $start integer or expresion evaluating to int
+ * @param mixed $length optional integer or expresion evaluating to int
+ * @return string sql fragment
+ */
+ public function sql_substr($expr, $start, $length=false) {
+ if (count(func_get_args()) < 2) {
+ throw new coding_exception('moodle_database::sql_substr() requires at least two parameters', 'Originaly this function wa
+s only returning name of SQL substring function, it now requires all parameters.');
+ }
+ if ($length === false) {
+ return "SUBSTRING($expr, $start, (LEN($expr) - $start + 1))";
+ } else {
+ return "SUBSTRING($expr, $start, $length)";
+ }
+ }
+
+/// session locking
+
+ public function session_lock_supported() {
+ return false;
+ }
+
+ public function get_session_lock($rowid) {
+ // NOTE: there is a potential locking problem for database running
+ // multiple instances of moodle, we could try to use pg_advisory_lock(int, int),
+ // luckily there is not a big chance that they would collide
+ if (!$this->session_lock_supported()) {
+ return;
+ }
+
+ parent::get_session_lock($rowid);
+ $sql = "SELECT pg_advisory_lock($rowid)";
+ $this->query_start($sql, null, SQL_QUERY_AUX);
+ $result = pg_query($this->pgsql, $sql);
+ $this->query_end($result);
+
+ if ($result) {
+ pg_free_result($result);
+ }
+ }
+
+ public function release_session_lock($rowid) {
+ if (!$this->session_lock_supported()) {
+ return;
+ }
+ parent::release_session_lock($rowid);
+
+ $sql = "SELECT pg_advisory_unlock($rowid)";
+ $this->query_start($sql, null, SQL_QUERY_AUX);
+ $result = pg_query($this->pgsql, $sql);
+ $this->query_end($result);
+
+ if ($result) {
+ pg_free_result($result);
+ }
+ }
+
+/// transactions
+
+ /**
+ * on DBs that support it, switch to transaction mode and begin a transaction
+ * you'll need to ensure you call commit_sql() or your changes *will* be lost.
+ *
+ * this is _very_ useful for massive updates
+ */
+ public function begin_sql() {
+ if (!parent::begin_sql()) {
+ return false;
+ }
+ $sql = "BEGIN TRANSACTION"; // Will be using READ COMMITTED isolation
+ $this->query_start($sql, NULL, SQL_QUERY_AUX);
+ $result = mssql_query($sql, $this->mssql);
+ $this->query_end($result);
+
+ $this->free_result($result);
+
+ return true;
+ }
+
+ /**
+ * on DBs that support it, commit the transaction
+ */
+ public function commit_sql() {
+ if (!parent::commit_sql()) {
+ return false;
+ }
+ $sql = "COMMIT TRANSACTION";
+ $this->query_start($sql, NULL, SQL_QUERY_AUX);
+ $result = mssql_query($sql, $this->mssql);
+ $this->query_end($result);
+
+ $this->free_result($result);
+
+ return true;
+ }
+
+ /**
+ * on DBs that support it, rollback the transaction
+ */
+ public function rollback_sql() {
+ if (!parent::rollback_sql()) {
+ return false;
+ }
+ $sql = "ROLLBACK TRANSACTION";
+ $this->query_start($sql, NULL, SQL_QUERY_AUX);
+ $result = mssql_query($sql, $this->mssql);
+ $this->query_end($result);
+
+ $this->free_result($result);
+
+ return true;
+ }
+}
projects / moodle.git / commitdiff