drupal/includes/database.pgsql.inc

377 lines
12 KiB
PHP

<?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) {
// Check if MySQL support is present in PHP
if (!function_exists('pg_connect')) {
drupal_maintenance_theme();
drupal_set_title('PHP PostgreSQL support not enabled');
print theme('maintenance_page', '<p>We were unable to use the PostgreSQL database because the PostgreSQL extension for PHP is not installed. Check your <code>PHP.ini</code> to see how you can enable it.</p>
<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;
}
$url = parse_url($url);
$conn_string = '';
// Decode url-encoded information in the db connection string
if (isset($url['user'])) {
$conn_string .= ' user=' . urldecode($url['user']);
}
if (isset($url['pass'])) {
$conn_string .= ' password=' . urldecode($url['pass']);
}
if (isset($url['host'])) {
$conn_string .= ' host=' . urldecode($url['host']);
}
if (isset($url['path'])) {
$conn_string .= ' dbname=' . substr(urldecode($url['path']), 1);
}
if (isset($url['port'])) {
$conn_string .= ' port=' . urldecode($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 (!$connection) {
drupal_maintenance_theme();
drupal_set_title('Unable to connect to database');
print theme('maintenance_page', '<p>If you still have to install Drupal, proceed to the <a href="'. base_path() .'install.php">installation page</a>.</p>
<p>If you have already finished installed Drupal, this either means that the username and password information in your <code>settings.php</code> file is incorrect or that we can\'t connect to the PostgreSQL database server. This could mean your hosting provider\'s database server is down.</p>
<p>The PostgreSQL error was: '. theme('placeholder', decode_entities($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)) {
$bt = debug_backtrace();
$query = $bt[2]['function'] . "\n" . $query;
list($usec, $sec) = explode(' ', microtime());
$stop = (float)$usec + (float)$sec;
$diff = $stop - $timer;
$queries[] = array($query, $diff);
}
if ($debug) {
print '<p>query: '. $query .'<br />error:'. pg_last_error($active_db) .'</p>';
}
if ($last_result !== FALSE) {
return $last_result;
}
else {
trigger_error(check_plain(pg_last_error($active_db) ."\nquery: ". $query), E_USER_WARNING);
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() {
global $active_db;
return pg_last_error($active_db);
}
/**
* 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.
* Valid %-modifiers are: %s, %d, %f, %b (binary data, do not enclose
* in '') and %%.
*
* NOTE: using this syntax will cast NULL and FALSE values to decimal 0,
* and TRUE values to decimal 1.
*
* @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);
array_shift($args);
$query = db_prefix_tables($query);
if (isset($args[0]) and is_array($args[0])) { // 'All arguments in one array' syntax
$args = $args[0];
}
_db_query_callback($args, TRUE);
$query = preg_replace_callback(DB_QUERY_REGEXP, '_db_query_callback', $query);
$query .= ' LIMIT '. (int)$count .' OFFSET '. (int)$from;
return _db_query($query);
}
/**
* Runs a SELECT query and stores its results in a temporary table.
*
* Use this as a substitute for db_query() when the results need to stored
* in a temporary table. Temporary tables exist for the duration of the page
* request.
* 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.
*
* Note that if you need to know how many results were returned, you should do
* a SELECT COUNT(*) on the temporary table afterwards. db_num_rows() and
* db_affected_rows() do not give consistent result across different database
* types in this case.
*
* @param $query
* A string containing a normal SELECT SQL query.
* @param ...
* A variable number of arguments which are substituted into the query
* using printf() syntax. The query arguments can be enclosed in one
* array instead.
* Valid %-modifiers are: %s, %d, %f, %b (binary data, do not enclose
* in '') and %%.
*
* NOTE: using this syntax will cast NULL and FALSE values to decimal 0,
* and TRUE values to decimal 1.
*
* @param $table
* The name of the temporary table to select into. This name will not be
* prefixed as there is no risk of collision.
* @return
* A database query result resource, or FALSE if the query was not executed
* correctly.
*/
function db_query_temporary($query) {
$args = func_get_args();
$tablename = array_pop($args);
array_shift($args);
$query = preg_replace('/^SELECT/i', 'CREATE TEMPORARY TABLE '. $tablename .' AS SELECT', db_prefix_tables($query));
if (isset($args[0]) and is_array($args[0])) { // 'All arguments in one array' syntax
$args = $args[0];
}
_db_query_callback($args, TRUE);
$query = preg_replace_callback(DB_QUERY_REGEXP, '_db_query_callback', $query);
return _db_query($query);
}
/**
* Returns a properly formatted Binary Large OBject value.
* In case of PostgreSQL encodes data for insert into bytea field.
*
* @param $data
* Data to encode.
* @return
* Encoded data.
*/
function db_encode_blob($data) {
return "'". pg_escape_bytea($data) ."'";
}
/**
* Returns text from a Binary Large OBject value.
* In case of PostgreSQL decodes data after select from bytea field.
*
* @param $data
* Data to decode.
* @return
* Decoded data.
*/
function db_decode_blob($data) {
return pg_unescape_bytea($data);
}
/**
* Prepare user input for use in a database query, preventing SQL injection attacks.
* Note: This function requires PostgreSQL 7.2 or later.
*/
function db_escape_string($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 {'. db_escape_table($table) .'} IN EXCLUSIVE MODE');
}
/**
* Unlock all locked tables.
* This function automatically commits a transaction.
*/
function db_unlock_tables() {
db_query('COMMIT');
}
/**
* Check if a table exists.
*/
function db_table_exists($table) {
return db_num_rows(db_query("SELECT relname FROM pg_class WHERE relname = '{" . db_escape_table($table) . "}'"));
}
/**
* Verify if the database is set up correctly.
*/
function db_check_setup() {
$encoding = db_result(db_query('SHOW server_encoding'));
if (!in_array(strtolower($encoding), array('unicode', 'utf8'))) {
drupal_set_message(t('Your PostgreSQL database is set up with the wrong character encoding (%encoding). It is possible it will not work as expected. It is advised to recreate it with UTF-8/Unicode encoding. More information can be found in the <a href="@url">PostgreSQL documentation</a>.', array('%encoding' => $encoding, '@url' => 'http://www.postgresql.org/docs/7.4/interactive/multibyte.html')), 'status');
}
}
/**
* @} End of "ingroup database".
*/