/lib/dml/sqlsrv_native_moodle_database.php
PHP | 1347 lines | 833 code | 170 blank | 344 comment | 118 complexity | 39230246d83cdf68d952a45ad2899293 MD5 | raw file
- <?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 2 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 sqlsrv class representing moodle database interface.
- *
- * @package core_dml
- * @copyright 2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
- * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v2 or later
- */
- defined('MOODLE_INTERNAL') || die();
- require_once(__DIR__.'/moodle_database.php');
- require_once(__DIR__.'/sqlsrv_native_moodle_recordset.php');
- require_once(__DIR__.'/sqlsrv_native_moodle_temptables.php');
- /**
- * Native sqlsrv class representing moodle database interface.
- *
- * @package core_dml
- * @copyright 2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
- * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v2 or later
- */
- class sqlsrv_native_moodle_database extends moodle_database {
- protected $sqlsrv = null;
- protected $last_error_reporting; // To handle SQL*Server-Native driver default verbosity
- protected $temptables; // Control existing temptables (sqlsrv_moodle_temptables object)
- protected $collation; // current DB collation cache
- /** @var array list of open recordsets */
- protected $recordsets = array();
- /**
- * Constructor - instantiates the database, specifying if it's external (connect to other systems) or no (Moodle DB)
- * note this has effect to decide if prefix checks must be performed or no
- * @param bool true means external database used
- */
- public function __construct($external=false) {
- parent::__construct($external);
- }
- /**
- * 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() {
- // use 'function_exists()' rather than 'extension_loaded()' because
- // the name used by 'extension_loaded()' is case specific! The extension
- // therefore *could be* mixed case and hence not found.
- if (!function_exists('sqlsrv_num_rows')) {
- if (stripos(PHP_OS, 'win') === 0) {
- return get_string('nativesqlsrvnodriver', 'install');
- } else {
- return get_string('nativesqlsrvnonwindows', 'install');
- }
- }
- return true;
- }
- /**
- * Returns database family type - describes SQL dialect
- * Note: can be used before connect()
- * @return string db family name (mysql, postgres, mssql, sqlsrv, oracle, etc.)
- */
- public function get_dbfamily() {
- return 'mssql';
- }
- /**
- * 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 'sqlsrv';
- }
- /**
- * 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('nativesqlsrv', 'install');
- }
- /**
- * Returns localised database configuration help.
- * Note: can be used before connect()
- * @return string
- */
- public function get_configuration_help() {
- return get_string('nativesqlsrvhelp', 'install');
- }
- /**
- * Returns localised database description
- * Note: can be used before connect()
- * @return string
- */
- public function get_configuration_hints() {
- $str = get_string('databasesettingssub_sqlsrv', 'install');
- $str .= "<p style='text-align:right'><a href=\"javascript:void(0)\" ";
- $str .= "onclick=\"return window.open('http://docs.moodle.org/en/Using_the_Microsoft_SQL_Server_Driver_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 most other methods. (you can call methods that return connection configuration parameters)
- * @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|bool The moodle db table name's prefix. false is 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) {
- $driverstatus = $this->driver_installed();
- if ($driverstatus !== true) {
- throw new dml_exception('dbdriverproblem', $driverstatus);
- }
- /*
- * Log all Errors.
- */
- sqlsrv_configure("WarningsReturnAsErrors", FALSE);
- sqlsrv_configure("LogSubsystems", SQLSRV_LOG_SYSTEM_OFF);
- sqlsrv_configure("LogSeverity", SQLSRV_LOG_SEVERITY_ERROR);
- $this->store_settings($dbhost, $dbuser, $dbpass, $dbname, $prefix, $dboptions);
- $this->sqlsrv = sqlsrv_connect($this->dbhost, array
- (
- 'UID' => $this->dbuser,
- 'PWD' => $this->dbpass,
- 'Database' => $this->dbname,
- 'CharacterSet' => 'UTF-8',
- 'MultipleActiveResultSets' => true,
- 'ConnectionPooling' => !empty($this->dboptions['dbpersist']),
- 'ReturnDatesAsStrings' => true,
- ));
- if ($this->sqlsrv === false) {
- $this->sqlsrv = null;
- $dberr = $this->get_last_error();
- throw new dml_connection_exception($dberr);
- }
- // Allow quoted identifiers
- $sql = "SET QUOTED_IDENTIFIER ON";
- $this->query_start($sql, null, SQL_QUERY_AUX);
- $result = sqlsrv_query($this->sqlsrv, $sql);
- $this->query_end($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(<>) symbols
- $sql = "SET ANSI_NULLS ON";
- $this->query_start($sql, null, SQL_QUERY_AUX);
- $result = sqlsrv_query($this->sqlsrv, $sql);
- $this->query_end($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);
- $result = sqlsrv_query($this->sqlsrv, $sql);
- $this->query_end($result);
- // Concatenating null with anything MUST return NULL
- $sql = "SET CONCAT_NULL_YIELDS_NULL ON";
- $this->query_start($sql, null, SQL_QUERY_AUX);
- $result = sqlsrv_query($this->sqlsrv, $sql);
- $this->query_end($result);
- $this->free_result($result);
- // Set transactions isolation level to READ_COMMITTED
- // prevents dirty reads when using transactions +
- // is the default isolation level of sqlsrv
- $sql = "SET TRANSACTION ISOLATION LEVEL READ COMMITTED";
- $this->query_start($sql, NULL, SQL_QUERY_AUX);
- $result = sqlsrv_query($this->sqlsrv, $sql);
- $this->query_end($result);
- $this->free_result($result);
- // Connection established and configured, going to instantiate the temptables controller
- $this->temptables = new sqlsrv_native_moodle_temptables($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 closing connection
- if ($this->sqlsrv) {
- sqlsrv_close($this->sqlsrv);
- $this->sqlsrv = null;
- }
- }
- /**
- * Called before each db query.
- * @param string $sql
- * @param array $params 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 Array containing 'description', 'version' and 'database' (current db) info
- */
- public function get_server_info() {
- static $info;
- if (!$info) {
- $server_info = sqlsrv_server_info($this->sqlsrv);
- if ($server_info) {
- $info['description'] = $server_info['SQLServerName'];
- $info['version'] = $server_info['SQLServerVersion'];
- $info['database'] = $server_info['CurrentDatabase'];
- }
- }
- return $info;
- }
- /**
- * Override: Converts short table name {tablename} to real table name
- * supporting temp tables (#) if detected
- *
- * @param string sql
- * @return string sql
- */
- protected function fix_table_names($sql) {
- if (preg_match_all('/\{([a-z][a-z0-9_]*)\}/i', $sql, $matches)) {
- foreach ($matches[0] as $key => $match) {
- $name = $matches[1][$key];
- if ($this->temptables->is_temptable($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
- */
- protected function allowed_param_types() {
- return SQL_PARAMS_QM; // sqlsrv 1.1 can bind
- }
- /**
- * Returns last error reported by database engine.
- * @return string error message
- */
- public function get_last_error() {
- $retErrors = sqlsrv_errors(SQLSRV_ERR_ALL);
- $errorMessage = 'No errors found';
- if ($retErrors != null) {
- $errorMessage = '';
- foreach ($retErrors as $arrError) {
- $errorMessage .= "SQLState: ".$arrError['SQLSTATE']."<br>\n";
- $errorMessage .= "Error Code: ".$arrError['code']."<br>\n";
- $errorMessage .= "Message: ".$arrError['message']."<br>\n";
- }
- }
- return $errorMessage;
- }
- /**
- * Prepare the query binding and do the actual query.
- *
- * @param string $sql The sql statement
- * @param array $params array of params for binding. If NULL, they are ignored.
- * @param int $sql_query_type - Type of operation
- * @param bool $free_result - Default true, transaction query will be freed.
- * @param bool $scrollable - Default false, to use for quickly seeking to target records
- * @return resource|bool result
- */
- private function do_query($sql, $params, $sql_query_type, $free_result = true, $scrollable = false) {
- list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
- /*
- * Bound variables *are* supported. Until I can get it to work, emulate the bindings
- * The challenge/problem/bug is that although they work, doing a SELECT SCOPE_IDENTITY()
- * doesn't return a value (no result set)
- *
- * -- somebody from MS
- */
- $sql = $this->emulate_bound_params($sql, $params);
- $this->query_start($sql, $params, $sql_query_type);
- if (!$scrollable) { // Only supporting next row
- $result = sqlsrv_query($this->sqlsrv, $sql);
- } else { // Supporting absolute/relative rows
- $result = sqlsrv_query($this->sqlsrv, $sql, array(), array('Scrollable' => SQLSRV_CURSOR_STATIC));
- }
- if ($result === false) {
- // TODO do something with error or just use if DEV or DEBUG?
- $dberr = $this->get_last_error();
- }
- $this->query_end($result);
- if ($free_result) {
- $this->free_result($result);
- return true;
- }
- return $result;
- }
- /**
- * 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 ($usecache and count($this->tables) > 0) {
- return $this->tables;
- }
- $this->tables = array ();
- $prefix = str_replace('_', '\\_', $this->prefix);
- $sql = "SELECT table_name
- FROM INFORMATION_SCHEMA.TABLES
- WHERE table_name LIKE '$prefix%' ESCAPE '\\' AND table_type = 'BASE TABLE'";
- $this->query_start($sql, null, SQL_QUERY_AUX);
- $result = sqlsrv_query($this->sqlsrv, $sql);
- $this->query_end($result);
- if ($result) {
- while ($row = sqlsrv_fetch_array($result)) {
- $tablename = reset($row);
- if ($this->prefix !== '') {
- if (strpos($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.
- * @param string $table The table we want to get indexes from.
- * @return array of arrays
- */
- public function get_indexes($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);
- $result = sqlsrv_query($this->sqlsrv, $sql);
- $this->query_end($result);
- if ($result) {
- $lastindex = '';
- $unique = false;
- $columns = array ();
- while ($row = sqlsrv_fetch_array($result, SQLSRV_FETCH_ASSOC)) {
- if ($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 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 and isset($this->columns[$table])) {
- return $this->columns[$table];
- }
- $this->columns[$table] = array ();
- if (!$this->temptables->is_temptable($table)) { // normal table, get metadata from own schema
- $sql = "SELECT column_name AS name,
- data_type AS type,
- numeric_precision AS max_length,
- character_maximum_length AS char_max_length,
- numeric_scale AS scale,
- is_nullable AS is_nullable,
- columnproperty(object_id(quotename(table_schema) + '.' + quotename(table_name)), column_name, 'IsIdentity') AS auto_increment,
- column_default AS default_value
- FROM INFORMATION_SCHEMA.COLUMNS
- WHERE table_name = '{".$table."}'
- ORDER BY ordinal_position";
- } else { // temp table, get metadata from tempdb schema
- $sql = "SELECT column_name AS name,
- data_type AS type,
- numeric_precision AS max_length,
- character_maximum_length AS char_max_length,
- numeric_scale AS scale,
- is_nullable AS is_nullable,
- columnproperty(object_id(quotename(table_schema) + '.' + quotename(table_name)), column_name, 'IsIdentity') AS auto_increment,
- column_default AS default_value
- FROM tempdb.INFORMATION_SCHEMA.COLUMNS ".
- // check this statement
- // JOIN tempdb..sysobjects ON name = table_name
- // WHERE id = object_id('tempdb..{".$table."}')
- "WHERE table_name LIKE '{".$table."}__________%'
- ORDER BY ordinal_position";
- }
- list($sql, $params, $type) = $this->fix_sql_params($sql, null);
- $this->query_start($sql, null, SQL_QUERY_AUX);
- $result = sqlsrv_query($this->sqlsrv, $sql);
- $this->query_end($result);
- if (!$result) {
- return array ();
- }
- while ($rawcolumn = sqlsrv_fetch_array($result, SQLSRV_FETCH_ASSOC)) {
- $rawcolumn = (object)$rawcolumn;
- $info = new stdClass();
- $info->name = $rawcolumn->name;
- $info->type = $rawcolumn->type;
- $info->meta_type = $this->sqlsrvtype2moodletype($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);
- if ($rawcolumn->default_value === NULL) {
- $info->default_value = NULL;
- } else {
- $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 $value value we are going to normalise
- * @return mixed the normalised value
- */
- protected function normalise_value($column, $value) {
- $this->detect_objects($value);
- if (is_bool($value)) { // Always, convert boolean to int
- $value = (int)$value;
- } // And continue processing because text columns with numeric info need special handling below
- 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') { // sqlsrv 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 sqlsrv_free_stmt(), avoiding some warnings without using the horrible @
- *
- * @param sqlsrv_resource $resource resource to be freed if possible
- * @return bool
- */
- private function free_result($resource) {
- if (!is_bool($resource)) { // true/false resources cannot be freed
- return sqlsrv_free_stmt($resource);
- }
- }
- /**
- * Provides mapping between sqlsrv native data types and moodle_database - database_column_info - ones)
- *
- * @param string $sqlsrv_type native sqlsrv data type
- * @return string 1-char database_column_info data type
- */
- private function sqlsrvtype2moodletype($sqlsrv_type) {
- $type = null;
- switch (strtoupper($sqlsrv_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('invalidsqlsrvnativetype', $sqlsrv_type);
- }
- return $type;
- }
- /**
- * Do NOT use in code, to be used by database_manager only!
- * @param string $sql query
- * @return bool true
- * @throws dml_exception A DML specific exception is thrown for any errors.
- */
- public function change_database_structure($sql) {
- $this->reset_caches();
- $this->query_start($sql, null, SQL_QUERY_STRUCTURE);
- $result = sqlsrv_query($this->sqlsrv, $sql);
- $this->query_end($result);
- return true;
- }
- /**
- * Prepare the array of params for native binding
- */
- protected function build_native_bound_params(array $params = null) {
- return null;
- }
- /**
- * Workaround for SQL*Server Native driver similar to MSSQL driver for
- * consistent behavior.
- */
- protected function emulate_bound_params($sql, array $params = null) {
- if (empty($params)) {
- return $sql;
- }
- // ok, we have verified sql statement with ? and correct number of params
- $parts = explode('?', $sql);
- $return = array_shift($parts);
- 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'"; // this is a hack for MDL-23997, we intentionally use string because it is compatible with both nvarchar and int types
- } else if (is_float($param)) {
- $return .= $param;
- } else {
- $param = str_replace("'", "''", $param);
- $return .= "N'$param'";
- }
- $return .= array_shift($parts);
- }
- 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 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 $params = null) {
- if (strpos($sql, ';') !== false) {
- throw new coding_exception('moodle_database::execute() Multiple sql statements found or bound parameters not used properly in query!');
- }
- $this->do_query($sql, $params, SQL_QUERY_UPDATE);
- 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 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) {
- $limitfrom = (int)$limitfrom;
- $limitnum = (int)$limitnum;
- $limitfrom = max(0, $limitfrom);
- $limitnum = max(0, $limitnum);
- if ($limitfrom or $limitnum) {
- if ($limitnum >= 1) { // Only apply TOP clause if we have any limitnum (limitfrom offset is handled later)
- $fetch = $limitfrom + $limitnum;
- if (PHP_INT_MAX - $limitnum < $limitfrom) { // Check PHP_INT_MAX overflow
- $fetch = PHP_INT_MAX;
- }
- $sql = preg_replace('/^([\s(])*SELECT([\s]+(DISTINCT|ALL))?(?!\s*TOP\s*\()/i',
- "\\1SELECT\\2 TOP $fetch", $sql);
- }
- }
- $result = $this->do_query($sql, $params, SQL_QUERY_SELECT, false, (bool)$limitfrom);
- if ($limitfrom) { // Skip $limitfrom records
- sqlsrv_fetch($result, SQLSRV_SCROLL_ABSOLUTE, $limitfrom - 1);
- }
- return $this->create_recordset($result);
- }
- /**
- * Create a record set and initialize with first row
- *
- * @param mixed $result
- * @return sqlsrv_native_moodle_recordset
- */
- protected function create_recordset($result) {
- $rs = new sqlsrv_native_moodle_recordset($result, $this);
- $this->recordsets[] = $rs;
- return $rs;
- }
- /**
- * Do not use outside of recordset class.
- * @internal
- * @param sqlsrv_native_moodle_recordset $rs
- */
- public function recordset_closed(sqlsrv_native_moodle_recordset $rs) {
- if ($key = array_search($rs, $this->recordsets, true)) {
- unset($this->recordsets[$key]);
- }
- }
- /**
- * 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) {
- $rs = $this->get_recordset_sql($sql, $params, $limitfrom, $limitnum);
- $results = array();
- foreach ($rs as $row) {
- $id = reset($row);
- if (isset($results[$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 $params array of sql parameters
- * @return array of values
- * @throws dml_exception A DML specific exception is thrown for any errors.
- */
- public function get_fieldset_sql($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 $returnid
- * @return bool|int true or new id
- * @throws dml_exception A DML specific exception is thrown for any errors.
- */
- public function insert_record_raw($table, $params, $returnid=true, $bulk=false, $customsequence=false) {
- if (!is_array($params)) {
- $params = (array)$params;
- }
- $isidentity = false;
- if ($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;
- $columns = $this->get_columns($table);
- if (isset($columns['id']) and $columns['id']->auto_increment) {
- $isidentity = true;
- }
- // Disable IDENTITY column before inserting record with id, only if the
- // column is identity, from meta information.
- if ($isidentity) {
- $sql = 'SET IDENTITY_INSERT {'.$table.'} ON'; // Yes, it' ON!!
- $this->do_query($sql, null, SQL_QUERY_AUX);
- }
- } else {
- unset($params['id']);
- }
- if (empty($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)";
- $query_id = $this->do_query($sql, $params, SQL_QUERY_INSERT);
- if ($customsequence) {
- // Enable IDENTITY column after inserting record with id, only if the
- // column is identity, from meta information.
- if ($isidentity) {
- $sql = 'SET IDENTITY_INSERT {'.$table.'} OFF'; // Yes, it' OFF!!
- $this->do_query($sql, null, SQL_QUERY_AUX);
- }
- }
- if ($returnid) {
- $id = $this->sqlsrv_fetch_id();
- return $id;
- } else {
- return true;
- }
- }
- /**
- * Get the ID of the current action
- *
- * @return mixed ID
- */
- private function sqlsrv_fetch_id() {
- $query_id = sqlsrv_query($this->sqlsrv, 'SELECT SCOPE_IDENTITY()');
- if ($query_id === false) {
- $dberr = $this->get_last_error();
- return false;
- }
- $row = $this->sqlsrv_fetchrow($query_id);
- return (int)$row[0];
- }
- /**
- * Fetch a single row into an numbered array
- *
- * @param mixed $query_id
- */
- private function sqlsrv_fetchrow($query_id) {
- $row = sqlsrv_fetch_array($query_id, SQLSRV_FETCH_NUMERIC);
- if ($row === false) {
- $dberr = $this->get_last_error();
- return false;
- }
- foreach ($row as $key => $value) {
- $row[$key] = ($value === ' ' || $value === NULL) ? '' : $value;
- }
- return $row;
- }
- /**
- * 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 $returnid Should the id of the newly created record entry be returned? If this option is not requested then true/false is returned.
- * @return bool|int true or new id
- * @throws dml_exception A DML specific exception is thrown for any errors.
- */
- public function insert_record($table, $dataobject, $returnid = true, $bulk = false) {
- $dataobject = (array)$dataobject;
- $columns = $this->get_columns($table);
- $cleaned = array ();
- foreach ($dataobject as $field => $value) {
- if ($field === 'id') {
- continue;
- }
- 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 $dataobject A data object with values for one or more fields in the record
- * @return bool true
- * @throws dml_exception A DML specific exception is thrown for any errors.
- */
- public function import_record($table, $dataobject) {
- if (!is_object($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);
- }
- $this->insert_record_raw($table, $cleaned, false, false, true);
- return true;
- }
- /**
- * Update record in database, as fast as possible, no safety checks, lobs not supported.
- * @param string $table name
- * @param mixed $params data record as object or array
- * @param bool true means repeated updates expected
- * @return bool true
- * @throws dml_exception A DML specific exception is thrown for any errors.
- */
- public function update_record_raw($table, $params, $bulk = false) {
- $params = (array)$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 = ?";
- $this->do_query($sql, $params, SQL_QUERY_UPDATE);
- 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 $dataobject An object with contents equal to fieldname=>fieldvalue. Must have an entry for 'id' to map to the table specified.
- * @param bool true means repeated updates expected
- * @return bool true
- * @throws dml_exception A DML specific exception is thrown for any errors.
- */
- public function update_record($table, $dataobject, $bulk = false) {
- $dataobject = (array)$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 $params array of sql parameters
- * @return bool true
- * @throws dml_exception A DML specific exception is thrown for any errors.
- */
- public function set_field_select($table, $newfield, $newvalue, $select, array $params = null) {
- if ($select) {
- $select = "WHERE $select";
- }
- if (is_null($params)) {
- $params = array ();
- }
- // convert params to ? types
- list($select, $params, $type) = $this->fix_sql_params($select, $params);
- // 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";
- $this->do_query($sql, $params, SQL_QUERY_UPDATE);
- 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 $params array of sql parameters
- * @return bool true
- * @throws dml_exception A DML specific exception is thrown for any errors.
- */
- public function delete_records_select($table, $select, array $params = null) {
- if ($select) {
- $select = "WHERE $select";
- }
- $sql = "DELETE FROM {".$table."} $select";
- // we use SQL_QUERY_UPDATE because we do not know what is in general SQL, delete constant would not be accurate
- $this->do_query($sql, $params, SQL_QUERY_UPDATE);
- return true;
- }
- public function sql_cast_char2int($fieldname, $text = false) {
- if (!$text) {
- return ' CAST(' . $fieldname . ' AS INT) ';
- } else {
- return ' CAST(' . $this->sql_compare_text($fieldname) . ' AS INT) ';
- }
- }
- public function sql_cast_char2real($fieldname, $text=false) {
- if (!$text) {
- return ' CAST(' . $fieldname . ' AS REAL) ';
- } else {
- return ' CAST(' . $this->sql_compare_text($fieldname) . ' AS REAL) ';
- }
- }
- public function sql_ceil($fieldname) {
- return ' CEILING('.$fieldname.')';
- }
- protected function get_collation() {
- if (isset($this->collation)) {
- return $this->collation;
- }
- if (!empty($this->dboptions['dbcollation'])) {
- // perf speedup
- $this->collation = $this->dboptions['dbcollation'];
- return $this->collation;
- }
- // make some default
- $this->collation = 'Latin1_General_CI_AI';
- $sql = "SELECT CAST(DATABASEPROPERTYEX('$this->dbname', 'Collation') AS varchar(255)) AS SQLCollation";
- $this->query_start($sql, null, SQL_QUERY_AUX);
- $result = sqlsrv_query($this->sqlsrv, $sql);
- $this->query_end($result);
- if ($result) {
- if ($rawcolumn = sqlsrv_fetch_array($result, SQLSRV_FETCH_ASSOC)) {
- $this->collation = reset($rawcolumn);
- }
- $this->free_result($result);
- }
- return $this->collation;
- }
- /**
- * Returns 'LIKE' part of a query.
- *
- * @param string $fieldname usually name of the table column
- * @param string $param usually bound query parameter (?, :named)
- * @param bool $casesensitive use case sensitive search
- * @param bool $accensensitive use accent sensitive search (not all databases support accent insensitive)
- * @param bool $notlike true means "NOT LIKE"
- * @param string $escapechar escape char for '%' and '_'
- * @return string SQL code fragment
- */
- public function sql_like($fieldname, $param, $casesensitive = true, $accentsensitive = true, $notlike = false, $escapechar = '\\') {
- if (strpos($param, '%') !== false) {
- debugging('Potential SQL injection detected, sql_like() expects bound parameters (? or :named)');
- }
- $collation = $this->get_collation();
- $LIKE = $notlike ? 'NOT LIKE' : 'LIKE';
- if ($casesensitive) {
- $collation = str_replace('_CI', '_CS', $collation);
- } else {
- $collation = str_replace('_CS', '_CI', $collation);
- }
- if ($accentsensitive) {
- $collation = str_replace('_AI', '_AS', $collation);
- } else {
- $collation = str_replace('_AS', '_AI', $collation);
- }
- return "$fieldname COLLATE $collation $LIKE $param ESCAPE '$escapechar'";
- }
- public function sql_concat() {
- $arr = func_get_args();
- foreach ($arr as $key => $ele) {
- $arr[$key] = ' CAST('.$ele.' AS NVARCHAR(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() SQL text used to extract substrings from DB
- * NOTE: this was originally returning only function name
- *
- * @param string $expr some string field, no aggregates
- * @param mixed $start integer or expression evaluating to int
- * @param mixed $length optional integer or expression evaluating to int
- * @return string sql fragment
- */
- public function sql_substr($expr, $start, $length = false) {
- if (count(func_get_args()) < 2) {
- throw new coding_exception('moodle_database::sql_substr() requires at least two parameters',
- 'Originally this function was only returning name of SQL substring function, it now requires all parameters.');
- }
- if ($length === false) {
- return "SUBSTRING($expr, $start, (LEN($expr) - $start + 1))";
- } else {
- return "SUBSTRING($expr, $start, $length)";
- }
- }
- public function session_lock_supported() {
- return true;
- }
- /**
- * Obtain session lock
- * @param int $rowid id of the row with session record
- * @param int $timeout max allowed time to wait for the lock in seconds
- * @return void
- */
- public function get_session_lock($rowid, $timeout) {
- if (!$this->session_lock_supported()) {
- return;
- }
- parent::get_session_lock($rowid, $timeout);
- $timeoutmilli = $timeout * 1000;
- $fullname = $this->dbname.'-'.$this->prefix.'-session-'.$rowid;
- // While this may work using proper {call sp_...} calls + binding +
- // executing + consuming recordsets, the solution used for the mssql
- // driver is working perfectly, so 100% mimic-ing that code.
- // $sql = "sp_getapplock '$fullname', 'Exclusive', 'Session', $timeoutmilli";
- $sql = "BEGIN
- DECLARE @result INT
- EXECUTE @result = sp_getapplock @Resource='$fullname',
- @LockMode='Exclusive',
- @LockOwner='Session',
- @LockTimeout='$timeoutmilli'
- SELECT @result
- END";
- $this->que