Chamilo is a learning management system focused on ease of use and accessibility
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chamilo-lms/main/inc/lib/database.lib.php

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<?php
/* For licensing terms, see /license.txt */
/**
* This is the main database library for Chamilo.
* Include/require it in your code to use its functionality.
*
* This library now uses a Doctrine DBAL Silex service provider
*
* @package chamilo.library
*/
/**
* Database class definition
* @package chamilo.database
*/
class Database
{
/**
* The main connection
*
* @var \Doctrine\DBAL\Connection
*/
private static $db;
/**
* Read connection
*
* @var \Doctrine\DBAL\Connection
*/
private static $connectionRead;
/**
* Write connection
*
* @var \Doctrine\DBAL\Connection
*/
private static $connectionWrite;
/**
* Constructor
*
* @param $db \Doctrine\DBAL\Connection
* @param array $dbs
*/
public function __construct($db, $dbs)
{
self::setDatabase($db, $dbs);
}
/**
* @param $db
* @param $dbs
*/
public function setDatabase($db, $dbs)
{
self::$db = $db;
// Using read/write connections see the services.php file
self::$connectionRead = isset($dbs['db_read']) ? $dbs['db_read'] : $db;
self::$connectionWrite = isset($dbs['db_write']) ? $dbs['db_write'] : $db;
}
/**
* Return current connection
* @return \Doctrine\DBAL\Connection
*/
public function getConnection()
{
return self::$db;
}
/* Variable use only in the installation process to log errors. See the Database::query function */
// static $log_queries = false;
/**
* Returns the name of the main database.
* @return string
*/
public static function get_main_database()
{
return self::$db->getDatabase();
}
/**
* The glue is the string needed between database and table.
* The trick is: in multiple databases, this is a period (with backticks).
* In single database, this can be e.g. an underscore so we just fake
* there are multiple databases and the code can be written independent
* of the single / multiple database setting.
* @return string
*/
public static function get_database_glue()
{
return `.`;
}
/*
Table name methods
Use these methods to get table names for queries,
instead of constructing them yourself.
Backticks automatically surround the result,
e.g. COURSE_NAME.link
so the queries can look cleaner.
Example:
$table = Database::get_course_table(TABLE_DOCUMENT);
$sql_query = "SELECT * FROM $table WHERE $condition";
$sql_result = Database::query($sql_query);
$result = Database::fetch_array($sql_result);
*/
/**
* This function returns the correct complete name of any table of the main
* database of which you pass the short name as a parameter.
* Define table names as constants in this library and use them
* instead of directly using magic words in your tool code.
*
* @param string $short_table_name, the name of the table
* @return string
*/
public static function get_main_table($short_table_name)
{
return self::format_table_name(self::get_main_database(), $short_table_name);
}
/**
* This method returns the correct complete name of any course table of
* which you pass the short name as a parameter.
* Define table names as constants in this library and use them
* instead of directly using magic words in your tool code.
*
* @param string $short_table_name, the name of the table
* @return string
*
*/
public static function get_course_table($short_table_name)
{
return self::format_table_name(self::get_main_database(), DB_COURSE_PREFIX.$short_table_name);
}
/**
* Returns the number of affected rows in the last database operation.
* @param \Doctrine\DBAL\Driver\Statement $result
* @return int
*/
public static function affected_rows(\Doctrine\DBAL\Driver\Statement $result = null)
{
return $result->rowCount();
//return self::use_default_connection($connection) ? mysql_affected_rows() : mysql_affected_rows($connection);
}
/**
* Gets the array from a SQL result (as returned by Database::query) - help achieving database independence
* @param resource The result from a call to sql_query (e.g. Database::query)
* @param string Optional: "ASSOC","NUM" or "BOTH", as the constant used in mysql_fetch_array.
* @return array Array of results as returned by php
* @author Yannick Warnier <yannick.warnier@beeznest.com>
*/
public static function fetch_array(\Doctrine\DBAL\Driver\Statement $result, $option = 'BOTH')
{
if ($result === false) {
return array();
}
return $result->fetch(self::customOptionToDoctrineOption($option));
/*return $option == 'ASSOC' ? mysql_fetch_array($result, MYSQL_ASSOC) : ($option == 'NUM' ? mysql_fetch_array(
$result,
MYSQL_NUM
) : mysql_fetch_array($result));*/
}
/**
* Gets an associative array from a SQL result (as returned by Database::query).
* This method is equivalent to calling Database::fetch_array() with 'ASSOC' value for the optional second parameter.
* @param resource $result The result from a call to sql_query (e.g. Database::query).
* @return array Returns an associative array that corresponds to the fetched row and moves the internal data pointer ahead.
*/
public static function fetch_assoc(\Doctrine\DBAL\Driver\Statement $result)
{
return $result->fetch(PDO::FETCH_ASSOC);
//return mysql_fetch_assoc($result);
}
/**
* Gets the next row of the result of the SQL query (as returned by Database::query) in an object form
* @param \Doctrine\DBAL\Driver\Statement The result from a call to Database::query())
* @param string Optional class name to instanciate
* @param array Optional array of parameters
* @return object Object of class StdClass or the required class, containing the query result row
* @author Yannick Warnier <yannick.warnier@dokeos.com>
*/
public static function fetch_object(\Doctrine\DBAL\Driver\Statement $result)
{
// Waiting for http://www.doctrine-project.org/jira/browse/DBAL-544 in order to know which constant use.
//return $result->fetch(\Doctrine\ORM\Query::HYDRATE_OBJECT);
return $result->fetch(PDO::FETCH_OBJ);
/*return !empty($class) ? (is_array($params) ? mysql_fetch_object($result, $class, $params) : mysql_fetch_object(
$result,
$class
)) : mysql_fetch_object($result);*/
}
/**
* Gets the array from a SQL result (as returned by Database::query) - help achieving database independence
* @param \Doctrine\DBAL\Driver\Statement The result from a call to Database::query())
* @return array Array of results as returned by php
*/
public static function fetch_row(\Doctrine\DBAL\Driver\Statement $result)
{
return $result->fetch(PDO::FETCH_NUM);
//return mysql_fetch_row($result);
}
/**
* Gets the ID of the last item inserted into the database
* @return int The last ID as returned by the DB function
*/
public static function insert_id()
{
return self::$connectionWrite->lastInsertId();
}
/**
* Gets the number of rows from the last query result - help achieving database independence
* @param \Doctrine\DBAL\Driver\Statement
* @return integer The number of rows contained in this result
**/
public static function num_rows(\Doctrine\DBAL\Driver\Statement $result)
{
return $result->rowCount();
}
/**
* Acts as the relative *_result() function of most DB drivers and fetches a
* specific line and a field
* @param \Doctrine\DBAL\Driver\Statement The database resource to get data from
* @param integer The row number
* @param string Optional field name or number
* @return mixed One cell of the result, or FALSE on error
*/
public static function result(\Doctrine\DBAL\Driver\Statement $resource, $row, $field = 0)
{
if ($resource->rowCount() > 0) {
$result = $resource->fetchAll(PDO::FETCH_BOTH);
return $result[$row][$field];
}
return null;
}
/**
* Frees all the memory associated with the provided result identifier.
* @return bool Returns TRUE on success or FALSE on failure.
* Notes: Use this method if you are concerned about how much memory is being used for queries that return large result sets.
* Anyway, all associated result memory is automatically freed at the end of the script's execution.
*/
public static function free_result(\Doctrine\DBAL\Driver\Statement $result)
{
$result->closeCursor();
//return mysql_free_result($result);
}
/**
* Detects if a query is going to modify something in the database in order to use the write connection
* @param string $query
* @return bool
*/
public static function isWriteQuery($query)
{
$isWriteQuery = preg_match("/UPDATE(.*) FROM/i", $query) ||
preg_match("/INSERT INTO/i", $query) ||
preg_match("/REPLACE INTO/i", $query) ||
preg_match("/DELETE FROM/i", $query);
return $isWriteQuery;
}
/**
* Escapes a string to insert into the database as text
* @param string The string to escape
* @return string The escaped string
*/
public static function escape_string($string)
{
/* The pdo::quote function adds a "'" character we need to remove that '
because in Chamilo, developers builds a query like this:
$sql = "SELECT * FROM $table WHERE id = 'Database::escape_string($id)'";
otherwise we will have an error because the query will be:
SELECT * FROM user WHERE id = ''1'' instead of
SELECT * FROM user WHERE id = '1'
*/
// $string = '_@_'.self::$db->quote($string).'_@_';
$string = self::$db->quote($string);
return trim($string, "'");
return $string;
}
/**
* Executes a query in the database
* @author Julio Montoya
* @param string $query The SQL query
* @return \Doctrine\DBAL\Driver\Statement
*/
public static function query($query)
{
$isWriteQuery = self::isWriteQuery($query);
if ($isWriteQuery) {
$connection = self::$connectionWrite;
} else {
$connection = self::$connectionRead;
}
/* The solution below does not work because there are some case where we use the "LIKE" option like this:
$sql = 'SELECT * FROM user WHERE id LIKE "%'.Database::escape_string($id).' %" ;
Chamilo queries are formed in many ways:
$sql = "SELECT * FROM user WHERE id = '".Database::escape_string($id)."'; or
$sql = 'SELECT * FROM user WHERE id = '.Database::escape_string($id).';
The problem here is that the function escape_string() calls the quote function that adds a "'" string.
Instead of this we're adding a identifier __@__ so we can identify those cases and replace with a simple '
*/
//var_dump($query);
/*$query = str_replace(
array(
"\"_@_'",
"'_@_\"",
"'_@_'",
"_@_'",
"'_@_",
),
"'",
$query
);*/
//var_dump($query);
return $connection->executeQuery($query);
}
public static function customOptionToDoctrineOption($option)
{
switch($option) {
case 'ASSOC':
return PDO::FETCH_ASSOC;
break;
case 'NUM':
return PDO::FETCH_NUM;
break;
case 'BOTH':
default:
return PDO::FETCH_BOTH;
break;
}
}
/**
* Stores a query result into an array.
* @param \Doctrine\DBAL\Driver\Statement $result - the return value of the query
* @param option BOTH, ASSOC, or NUM
* @return array - the value returned by the query
*/
public static function store_result(\Doctrine\DBAL\Driver\Statement $result, $option = 'BOTH')
{
return $result->fetchAll(self::customOptionToDoctrineOption($option));
/*
var_dump($a );
$array = array();
if ($result !== false) { // For isolation from database engine's behaviour.
while ($row = self::fetch_array($result, $option)) {
$array[] = $row;
}
}
return $array;*/
}
/*
Private methods
You should not access these from outside the class
No effort is made to keep the names / results the same.
*/
/**
* Structures a database and table name to ready them
* for querying. The database parameter is considered not glued,
* just plain e.g. COURSE001
* @todo not sure if we need this now
*/
private static function format_table_name($database, $table)
{
/*$glue = '`.`';
$table_name = '`'.$database.$glue.$table.'`';
*/
return $table;
//return $table_name;
}
/*
New useful DB functions
*/
/**
* Executes an insert to in the database (dbal already escape strings)
* @param string table name
* @param array An array of field and values
* @param bool show query
* @return int the id of the latest executed query
*/
public static function insert($table_name, $attributes, $show_query = false)
{
$result = self::$connectionWrite->insert($table_name, $attributes);
if ($result) {
return self::insert_id();
}
return false;
}
/**
* Experimental useful database finder
* @todo lot of stuff to do here
* @todo known issues, it doesn't work when using LIKE conditions
* @example array('where'=> array('course_code LIKE "?%"'))
* @example array('where'=> array('type = ? AND category = ?' => array('setting', 'Plugins'))
* @example array('where'=> array('name = "Julio" AND lastname = "montoya"))
*/
public static function select($columns, $table_name, $conditions = array(), $type_result = 'all', $option = 'ASSOC')
{
//$qb = self::$db->createQueryBuilder();
$conditions = self::parse_conditions($conditions);
//@todo we could do a describe here to check the columns ...
$clean_columns = '';
if (is_array($columns)) {
$clean_columns = implode(',', $columns);
} else {
if ($columns == '*') {
$clean_columns = '*';
} else {
$clean_columns = (string)$columns;
}
}
/*$qb->select($clean_columns);
$qb->from($table_name, 'table');
$qb->orderBy('table.' . $sort_order, 'ASC');*/
$sql = "SELECT $clean_columns FROM $table_name $conditions";
//var_dump($sql);
$result = self::query($sql);
$array = array();
if ($type_result == 'all') {
while ($row = self::fetch_array($result, $option)) {
if (isset($row['id'])) {
$array[$row['id']] = $row;
} else {
$array[] = $row;
}
}
} else {
$array = self::fetch_array($result, $option);
}
return $array;
}
/**
* Parses WHERE/ORDER conditions i.e array('where'=>array('id = ?' =>'4'), 'order'=>'id DESC'))
* @todo known issues, it doesn't work when using LIKE conditions example: array('where'=>array('course_code LIKE "?%"'))
* @param array
* @return string
* @todo lot of stuff to do here
*/
static function parse_conditions($conditions)
{
if (empty($conditions)) {
return '';
}
$return_value = $where_return = '';
foreach ($conditions as $type_condition => $condition_data) {
if ($condition_data == false) {
continue;
}
$type_condition = strtolower($type_condition);
switch ($type_condition) {
case 'where':
foreach ($condition_data as $condition => $value_array) {
if (is_array($value_array)) {
$clean_values = array();
foreach ($value_array as $item) {
$item = Database::escape_string($item);
$clean_values[] = $item;
}
} else {
$value_array = Database::escape_string($value_array);
$clean_values = $value_array;
}
if (!empty($condition) && $clean_values != '') {
$condition = str_replace('%', "'@percentage@'", $condition); //replace "%"
$condition = str_replace("'?'", "%s", $condition);
$condition = str_replace("?", "%s", $condition);
$condition = str_replace("@%s@", "@-@", $condition);
$condition = str_replace("%s", "'%s'", $condition);
$condition = str_replace("@-@", "@%s@", $condition);
//Treat conditons as string
$condition = vsprintf($condition, $clean_values);
$condition = str_replace('@percentage@', '%', $condition); //replace "%"
$where_return .= $condition;
}
}
if (!empty($where_return)) {
$return_value = " WHERE $where_return";
}
break;
case 'order':
$order_array = $condition_data;
if (!empty($order_array)) {
// 'order' => 'id desc, name desc'
$order_array = $order_array;
$new_order_array = explode(',', $order_array);
$temp_value = array();
foreach ($new_order_array as $element) {
$element = explode(' ', $element);
$element = array_filter($element);
$element = array_values($element);
if (!empty($element[1])) {
$element[1] = strtolower($element[1]);
$order = 'DESC';
if (in_array($element[1], array('desc', 'asc'))) {
$order = $element[1];
}
$temp_value[] = $element[0].' '.$order.' ';
} else {
//by default DESC
$temp_value[] = $element[0].' DESC ';
}
}
if (!empty($temp_value)) {
$return_value .= ' ORDER BY '.implode(', ', $temp_value);
}
}
break;
case 'limit':
$limit_array = explode(',', $condition_data);
if (!empty($limit_array)) {
if (count($limit_array) > 1) {
$return_value .= ' LIMIT '.intval($limit_array[0]).' , '.intval($limit_array[1]);
} else {
$return_value .= ' LIMIT '.intval($limit_array[0]);
}
}
break;
}
}
return $return_value;
}
/**
* @param array $conditions
* @return string
*/
public static function parse_where_conditions($conditions)
{
return self::parse_conditions(array('where' => $conditions));
}
/**
* Deletes an item depending of conditions
* @param string $table_name
* @param array $where_conditions
* @param bool $show_query
* @return int
*/
public static function delete($table_name, $where_conditions, $show_query = false)
{
//return self::$connectionWrite->delete($table_name, $where_conditions);
$where_return = self::parse_where_conditions($where_conditions);
$sql = "DELETE FROM $table_name $where_return ";
if ($show_query) {
echo $sql;
echo '<br />';
}
$result = self::query($sql);
$affected_rows = self::affected_rows($result);
//@todo should return affected_rows for
return $affected_rows;
}
/**
* Experimental useful database update
* @param string table name use Database::get_main_table
* @param array array with values to updates, keys are the fields in the database:
* @example: $params['name'] = 'Julio'; $params['lastname'] = 'Montoya';
* @param array where conditions i.e array('id = ?' =>'4')
* @param bool show query
* @todo lot of stuff to do here
*/
public static function update($table_name, $attributes, $where_conditions = array(), $show_query = false)
{
if (!empty($table_name) && !empty($attributes)) {
$update_sql = '';
//Cleaning attributes
$count = 1;
foreach ($attributes as $key => $value) {
if (!is_array($value)) {
$value = self::escape_string($value);
}
$update_sql .= "$key = '$value' ";
if ($count < count($attributes)) {
$update_sql .= ', ';
}
$count++;
}
if (!empty($update_sql)) {
//Parsing and cleaning the where conditions
$where_return = self::parse_where_conditions($where_conditions);
$sql = "UPDATE $table_name SET $update_sql $where_return ";
if ($show_query) {
var_dump($sql);
}
$result = self::query($sql);
$affected_rows = self::affected_rows($result);
return $affected_rows;
}
}
return false;
}
/**
* Counts the number of rows in a table
* @param string $table The table of which the rows should be counted
* @return int The number of rows in the given table.
*/
public static function count_rows($table)
{
$obj = self::fetch_object(self::query("SELECT COUNT(*) AS n FROM $table"));
return $obj->n;
}
/**
* Returns a list of tables within a database. The list may contain all of the
* available table names or filtered table names by using a pattern.
* @param string $database (optional) The name of the examined database.
* @param string $pattern (optional) A pattern for filtering table names as if it was needed for the SQL's LIKE clause, for example 'access_%'.
* @deprecated
* @return array Returns in an array the retrieved list of table names.
*/
public static function get_tables($database = '', $pattern = '')
{
$result = array();
$query = "SHOW TABLES";
if (!empty($database)) {
$query .= " FROM `".self::escape_string($database)."`";
}
if (!empty($pattern)) {
$query .= " LIKE '".self::escape_string($pattern)."'";
}
$query_result = Database::query($query);
while ($row = Database::fetch_row($query_result)) {
$result[] = $row[0];
}
return $result;
}
/**
* Returns a list of databases created on the server. The list may contain all of the
* available database names or filtered database names by using a pattern.
* @return array Returns in an array the retrieved list of database names.
*/
public static function get_databases()
{
$sm = self::$db->getSchemaManager();
return $sm->listDatabases();
}
}