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database.pgsql.inc
#22911 by Cvgbe: fixed table locking in PostgreSQL. You'll have to
Dries Buytaert authored
use db_lock_table() and db_unlock_tables() for your code to be compatible.
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database.pgsql.inc 7.82 KiB
<?php
// $Id$
/**
* @file
* Database interface code for PostgreSQL database servers.
*/
/**
* @ingroup database
* @{
*/
/**
* Initialize a database connection.
*
* Note that you can change the pg_connect() call to pg_pconnect() if you
* want to use persistent connections. This is not recommended on shared hosts,
* and might require additional database/webserver tuning. It can increase
* performance, however, when the overhead to connect to your database is high
* (e.g. your database and web server live on different machines).
*/
function db_connect($url) {
$url = parse_url($url);
$conn_string = ' user='. $url['user'] .' dbname='. substr($url['path'], 1) .' password='. $url['pass'] . ' host=' . $url['host'];
$conn_string .= isset($url['port']) ? ' port=' . $url['port'] : '';
// pg_last_error() does not return a useful error message for database
// connection errors. We must turn on error tracking to get at a good error
// message, which will be stored in $php_errormsg.
$track_errors_previous = ini_get('track_errors');
ini_set('track_errors', 1);
$connection = @pg_connect($conn_string);
if (!$connection) {
drupal_maintenance_theme();
drupal_set_title('Unable to connect to database');
print theme('maintenance_page', '<p>This either means that the database information in your <code>settings.php</code> file is incorrect or we can\'t contact the PostgreSQL database server. This could mean your hosting provider\'s database server is down.</p>
<p>The PostgreSQL error was: '. theme('placeholder', decode_entities($php_errormsg)) .'</p>
<p>Currently, the database is '. theme('placeholder', substr($url['path'], 1)) .', the username is '. theme('placeholder', $url['user']) .', and the database server is '. theme('placeholder', $url['host']) .'.</p>
<ul>
<li>Are you sure you have the correct username and password?</li>
<li>Are you sure that you have typed the correct hostname?</li>
<li>Are you sure you have the correct database name?</li>
<li>Are you sure that the database server is running?</li>
</ul>
<p>For more help, see the <a href="http://drupal.org/node/258">Installation and upgrading handbook</a>. If you are unsure what these terms mean you should probably contact your hosting provider.</p>');
exit;
}
// Restore error tracking setting
ini_set('track_errors', $track_errors_previous);
return $connection;
}
/**
* Helper function for db_query().
*/
function _db_query($query, $debug = 0) {
global $active_db, $last_result, $queries;
if (variable_get('dev_query', 0)) {
list($usec, $sec) = explode(' ', microtime());
$timer = (float)$usec + (float)$sec;
}
$last_result = pg_query($active_db, $query);
if (variable_get('dev_query', 0)) {
list($usec, $sec) = explode(' ', microtime());
$stop = (float)$usec + (float)$sec;
$diff = $stop - $timer;
$queries[] = array($query, $diff);
}
if ($debug) {
print '<p>query: '. $query .'<br />error:'. pg_last_error() .'</p>';
}
if ($last_result !== FALSE) {
return $last_result;
}
else {
trigger_error(pg_last_error() ."\nquery: ". htmlspecialchars($query), E_USER_ERROR);
return FALSE;
}
}
/**
* Fetch one result row from the previous query as an object.
*
* @param $result
* A database query result resource, as returned from db_query().
* @return
* An object representing the next row of the result. The attributes of this
* object are the table fields selected by the query.
*/
function db_fetch_object($result) {
if ($result) {
return pg_fetch_object($result);
}
}
/**
* Fetch one result row from the previous query as an array.
*
* @param $result
* A database query result resource, as returned from db_query().
* @return
* An associative array representing the next row of the result. The keys of
* this object are the names of the table fields selected by the query, and
* the values are the field values for this result row.
*/
function db_fetch_array($result) {
if ($result) {
return pg_fetch_assoc($result);
}
}
/**
* Determine how many result rows were found by the preceding query.
*
* @param $result
* A database query result resource, as returned from db_query().
* @return
* The number of result rows.
*/
function db_num_rows($result) {
if ($result) {
return pg_num_rows($result);
}
}
/**
* Return an individual result field from the previous query.
*
* Only use this function if exactly one field is being selected; otherwise,
* use db_fetch_object() or db_fetch_array(). *
* @param $result
* A database query result resource, as returned from db_query().
* @param $row
* The index of the row whose result is needed.
* @return
* The resulting field.
*/
function db_result($result, $row = 0) {
if ($result && pg_num_rows($result) > $row) {
$res = pg_fetch_row($result, $row);
return $res[0];
}
}
/**
* Determine whether the previous query caused an error.
*/
function db_error() {
return pg_last_error();
}
/**
* Return a new unique ID in the given sequence.
*
* For compatibility reasons, Drupal does not use auto-numbered fields in its
* database tables. Instead, this function is used to return a new unique ID
* of the type requested. If necessary, a new sequence with the given name
* will be created.
*/
function db_next_id($name) {
$id = db_result(db_query("SELECT nextval('%s_seq')", db_prefix_tables($name)));
return $id;
}
/**
* Determine the number of rows changed by the preceding query.
*/
function db_affected_rows() {
global $last_result;
return pg_affected_rows($last_result);
}
/**
* Runs a limited-range query in the active database.
*
* Use this as a substitute for db_query() when a subset of the query is to be
* returned.
* User-supplied arguments to the query should be passed in as separate parameters
* so that they can be properly escaped to avoid SQL injection attacks.
*
* @param $query
* A string containing an SQL query.
* @param ...
* A variable number of arguments which are substituted into the query using
* printf() syntax. Instead of a variable number of query arguments, you may
* also pass a single array containing the query arguments.
* @param $from
* The first result row to return.
* @param $count
* The maximum number of result rows to return.
* @return
* A database query result resource, or FALSE if the query was not executed
* correctly.
*/
function db_query_range($query) {
$args = func_get_args();
$count = array_pop($args);
$from = array_pop($args);
$query = db_prefix_tables($query);
if (count($args) > 1) {
// Check for array (alternative syntax).
if (is_array($args[1])) {
$args = array_merge(array($query), $args[1]);
}
$args = array_map('db_escape_string', $args);
$args[0] = $query;
$query = call_user_func_array('sprintf', $args);
}
$query .= ' LIMIT '. $count .' OFFSET '. $from;
return _db_query($query);
}
/**
* Returns a properly formatted Binary Large OBject value.
*
* @param $data
* Data to encode.
* @return
* Encoded data.
*/
function db_encode_blob($data) {
return addcslashes($data, "\0..\37\\");
}
/**
* Returns text from a Binary Large OBject value.
*
* @param $data
* Data to decode.
* @return
* Decoded data.
*/
function db_decode_blob($data) {
return stripcslashes($data);
}
/**
* Prepare user input for use in a database query, preventing SQL injection attacks.
* Note: This function requires PostgreSQL 7.2 or later.
*/
function db_escape_string($text) {
return pg_escape_string($text);
}
/**
* Lock a table.
* This function automatically starts a transaction.
*/
function db_lock_table($table) {
db_query('BEGIN; LOCK TABLE {%s} IN EXCLUSIVE MODE', $table);
}
/**
* Unlock all locked tables.
* This function automatically commits a transation.
*/
function db_unlock_tables() {
db_query('COMMIT');
}
/**
* @} End of "ingroup database".
*/