diff options
Diffstat (limited to 'engine/lib')
| -rw-r--r-- | engine/lib/database.php | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/engine/lib/database.php b/engine/lib/database.php new file mode 100644 index 000000000..0511ee82b --- /dev/null +++ b/engine/lib/database.php @@ -0,0 +1,231 @@ +<?php
+
+ /**
+ * Elgg database
+ * Contains database connection and transfer functionality
+ *
+ * @package Elgg
+ * @subpackage Core
+ * @license http://www.gnu.org/licenses/old-licenses/gpl-2.0.html GNU Public License version 2
+ * @author Curverider Ltd
+ * @copyright Curverider Ltd 2008
+ * @link http://elgg.org/
+ */
+
+ /**
+ * Connect to the database server and use the Elgg database for a particular database link
+ *
+ * @param string $dblinkname Default "readwrite"; you can change this to set up additional global database links, eg "read" and "write"
+ */
+ function establish_db_link($dblinkname = "readwrite") {
+
+ // Get configuration, and globalise database link
+ global $CONFIG, $dblink;
+
+ if (!isset($dblink)) {
+ $dblink = array();
+ }
+
+ if ($dblinkname != "readwrite" && isset($CONFIG->db[$dblinkname])) {
+ if (is_array($CONFIG->db[$dblinkname])) {
+ $index = rand(0,sizeof($CONFIG->db[$dblinkname]));
+ $dbhost = $CONFIG->db[$dblinkname][$index]->dbhost;
+ $dbuser = $CONFIG->db[$dblinkname][$index]->dbuser;
+ $dbpass = $CONFIG->db[$dblinkname][$index]->dbpass;
+ $dbname = $CONFIG->db[$dblinkname][$index]->dbname;
+ } else {
+ $dbhost = $CONFIG->db[$dblinkname]->dbhost;
+ $dbuser = $CONFIG->db[$dblinkname]->dbuser;
+ $dbpass = $CONFIG->db[$dblinkname]->dbpass;
+ $dbname = $CONFIG->db[$dblinkname]->dbname;
+ }
+ } else {
+ $dbhost = $CONFIG->dbhost;
+ $dbuser = $CONFIG->dbuser;
+ $dbpass = $CONFIG->dbpass;
+ $dbname = $CONFIG->dbname;
+ }
+
+ // Connect to database
+ if (!$dblink[$dblinkname] = mysql_connect($CONFIG->dbhost, $CONFIG->dbuser, $CONFIG->dbpass, true))
+ throw new DatabaseException("Elgg couldn't connect to the database using the given credentials.");
+ if (!mysql_select_db($CONFIG->dbname, $dblink[$dblinkname]))
+ throw new DatabaseException("Elgg couldn't select the database {$CONFIG->dbname}.");
+
+ }
+
+ /**
+ * Establish all database connections
+ *
+ * If the configuration has been set up for multiple read/write databases, set those
+ * links up separately; otherwise just create the one database link
+ *
+ */
+
+ function setup_db_connections() {
+
+ // Get configuration and globalise database link
+ global $CONFIG, $dblink;
+
+ if (!empty($CONFIG->db->split)) {
+ establish_db_link('read');
+ establish_db_link('write');
+ } else {
+ establish_db_link('readwrite');
+ }
+
+ }
+
+ /**
+ * Alias to setup_db_connections, for use in the event handler
+ *
+ * @param string $event The event type
+ * @param string $object_type The object type
+ * @param mixed $object Used for nothing in this context
+ */
+ function init_db($event, $object_type, $object = null) {
+ setup_db_connections();
+ }
+
+ /**
+ * Gets the appropriate db link for the operation mode requested
+ *
+ * @param string $dblinktype The type of link we want - "read", "write" or "readwrite" (the default)
+ * @return database link
+ */
+ function get_db_link($dblinktype) {
+
+ global $dblink;
+
+ if (isset($dblink[$dblinktype])) {
+ return $dblink[$dblinktype];
+ } else {
+ return $dblink['readwrite'];
+ }
+
+ }
+
+ /**
+ * Use this function to get data from the database
+ * @param $query The query being passed.
+ */
+
+ function get_data($query) {
+
+ global $dbcalls;
+
+ $dblink = get_db_link('read');
+
+ $resultarray = array();
+ $dbcalls++;
+
+ if ($result = mysql_query($query, $dblink)) {
+ while ($row = mysql_fetch_object($result)) {
+ $resultarray[] = $row;
+ }
+ }
+ if (empty($resultarray)) {
+ return false;
+ }
+ return $resultarray;
+ }
+
+ /**
+ * Use this function to get a single data row from the database
+ * @param $query The query to run.
+ */
+
+ function get_data_row($query) {
+
+ global $dbcalls;
+
+ $dblink = get_db_link('read');
+
+ $dbcalls++;
+
+ if ($result = mysql_query($query, $dblink)) {
+ while ($row = mysql_fetch_object($result)) {
+ return $row;
+ }
+ }
+ return false;
+ }
+
+ /**
+ * Use this function to insert database data; returns id or false
+ * @param $query The query to run.
+ * @return $id the database id of the inserted row.
+ */
+
+ function insert_data($query) {
+
+ global $dbcalls;
+
+ $dblink = get_db_link('write');
+
+ $dbcalls++;
+
+ if (mysql_query($query, $dblink)) {
+ return mysql_insert_id($dblink);
+ } else {
+ return false;
+ }
+
+ }
+
+ /**
+ * Use this function to update database data
+ * @param $query The query to run.
+ */
+
+ function update_data($query) {
+
+ global $dbcalls;
+
+ $dblink = get_db_link('write');
+
+ $dbcalls++;
+
+ if (mysql_query($query, $dblink))
+ return mysql_affected_rows();
+
+ return false;
+
+ }
+
+ // Use this function to delete a record
+
+ function delete_record($query) {
+
+ global $dbcalls;
+
+ $dblink = get_db_link('write');
+
+ $dbcalls++;
+
+ if (mysql_query($query, $dblink)) {
+ return mysql_affected_rows();
+ } else {
+ return false;
+ }
+
+ }
+
+ /**
+ * Returns the number of rows returned by the last select statement, without the need to re-execute the query.
+ * This is MYSQL specific.
+ *
+ * @return int
+ */
+ function count_last_select() {
+ $row = get_data_row("SELECT found_rows() as count");
+ if ($row)
+ return $row->count;
+ return 0;
+ }
+
+ // Stuff for initialisation
+
+ register_event_handler('init','system','init_db',0);
+
+?>
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