Added PEAR:DB support plus database replication support

1 files changed, 1097 insertions, 0 deletions

diff --git a/program/lib/DB/pgsql.php b/program/lib/DB/pgsql.php
new file mode 100644
index 000000000..ae229afa1
--- /dev/null
+++ b/program/lib/DB/pgsql.php
@@ -0,0 +1,1097 @@
+<?php
+
+/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
+
+/**
+ * The PEAR DB driver for PHP's pgsql extension
+ * for interacting with PostgreSQL databases
+ *
+ * PHP versions 4 and 5
+ *
+ * LICENSE: This source file is subject to version 3.0 of the PHP license
+ * that is available through the world-wide-web at the following URI:
+ * http://www.php.net/license/3_0.txt.  If you did not receive a copy of
+ * the PHP License and are unable to obtain it through the web, please
+ * send a note to license@php.net so we can mail you a copy immediately.
+ *
+ * @category   Database
+ * @package    DB
+ * @author     Rui Hirokawa <hirokawa@php.net>
+ * @author     Stig Bakken <ssb@php.net>
+ * @author     Daniel Convissor <danielc@php.net>
+ * @copyright  1997-2005 The PHP Group
+ * @license    http://www.php.net/license/3_0.txt  PHP License 3.0
+ * @version    CVS: $Id$
+ * @link       http://pear.php.net/package/DB
+ */
+
+/**
+ * Obtain the DB_common class so it can be extended from
+ */
+require_once 'DB/common.php';
+
+/**
+ * The methods PEAR DB uses to interact with PHP's pgsql extension
+ * for interacting with PostgreSQL databases
+ *
+ * These methods overload the ones declared in DB_common.
+ *
+ * @category   Database
+ * @package    DB
+ * @author     Rui Hirokawa <hirokawa@php.net>
+ * @author     Stig Bakken <ssb@php.net>
+ * @author     Daniel Convissor <danielc@php.net>
+ * @copyright  1997-2005 The PHP Group
+ * @license    http://www.php.net/license/3_0.txt  PHP License 3.0
+ * @version    Release: @package_version@
+ * @link       http://pear.php.net/package/DB
+ */
+class DB_pgsql extends DB_common
+{
+    // {{{ properties
+
+    /**
+     * The DB driver type (mysql, oci8, odbc, etc.)
+     * @var string
+     */
+    var $phptype = 'pgsql';
+
+    /**
+     * The database syntax variant to be used (db2, access, etc.), if any
+     * @var string
+     */
+    var $dbsyntax = 'pgsql';
+
+    /**
+     * The capabilities of this DB implementation
+     *
+     * The 'new_link' element contains the PHP version that first provided
+     * new_link support for this DBMS.  Contains false if it's unsupported.
+     *
+     * Meaning of the 'limit' element:
+     *   + 'emulate' = emulate with fetch row by number
+     *   + 'alter'   = alter the query
+     *   + false     = skip rows
+     *
+     * @var array
+     */
+    var $features = array(
+        'limit'         => 'alter',
+        'new_link'      => '4.3.0',
+        'numrows'       => true,
+        'pconnect'      => true,
+        'prepare'       => false,
+        'ssl'           => true,
+        'transactions'  => true,
+    );
+
+    /**
+     * A mapping of native error codes to DB error codes
+     * @var array
+     */
+    var $errorcode_map = array(
+    );
+
+    /**
+     * The raw database connection created by PHP
+     * @var resource
+     */
+    var $connection;
+
+    /**
+     * The DSN information for connecting to a database
+     * @var array
+     */
+    var $dsn = array();
+
+
+    /**
+     * Should data manipulation queries be committed automatically?
+     * @var bool
+     * @access private
+     */
+    var $autocommit = true;
+
+    /**
+     * The quantity of transactions begun
+     *
+     * {@internal  While this is private, it can't actually be designated
+     * private in PHP 5 because it is directly accessed in the test suite.}}
+     *
+     * @var integer
+     * @access private
+     */
+    var $transaction_opcount = 0;
+
+    /**
+     * The number of rows affected by a data manipulation query
+     * @var integer
+     */
+    var $affected = 0;
+
+    /**
+     * The current row being looked at in fetchInto()
+     * @var array
+     * @access private
+     */
+    var $row = array();
+
+    /**
+     * The number of rows in a given result set
+     * @var array
+     * @access private
+     */
+    var $_num_rows = array();
+
+
+    // }}}
+    // {{{ constructor
+
+    /**
+     * This constructor calls <kbd>$this->DB_common()</kbd>
+     *
+     * @return void
+     */
+    function DB_pgsql()
+    {
+        $this->DB_common();
+    }
+
+    // }}}
+    // {{{ connect()
+
+    /**
+     * Connect to the database server, log in and open the database
+     *
+     * Don't call this method directly.  Use DB::connect() instead.
+     *
+     * PEAR DB's pgsql driver supports the following extra DSN options:
+     *   + connect_timeout  How many seconds to wait for a connection to
+     *                       be established.  Available since PEAR DB 1.7.0.
+     *   + new_link         If set to true, causes subsequent calls to
+     *                       connect() to return a new connection link
+     *                       instead of the existing one.  WARNING: this is
+     *                       not portable to other DBMS's.  Available only
+     *                       if PHP is >= 4.3.0 and PEAR DB is >= 1.7.0.
+     *   + options          Command line options to be sent to the server.
+     *                       Available since PEAR DB 1.6.4.
+     *   + service          Specifies a service name in pg_service.conf that
+     *                       holds additional connection parameters.
+     *                       Available since PEAR DB 1.7.0.
+     *   + sslmode          How should SSL be used when connecting?  Values:
+     *                       disable, allow, prefer or require.
+     *                       Available since PEAR DB 1.7.0.
+     *   + tty              This was used to specify where to send server
+     *                       debug output.  Available since PEAR DB 1.6.4.
+     *
+     * Example of connecting to a new link via a socket:
+     * <code>
+     * require_once 'DB.php';
+     * 
+     * $dsn = 'pgsql://user:pass@unix(/tmp)/dbname?new_link=true';
+     * $options = array(
+     *     'portability' => DB_PORTABILITY_ALL,
+     * );
+     * 
+     * $db =& DB::connect($dsn, $options);
+     * if (PEAR::isError($db)) {
+     *     die($db->getMessage());
+     * }
+     * </code>
+     *
+     * @param array $dsn         the data source name
+     * @param bool  $persistent  should the connection be persistent?
+     *
+     * @return int  DB_OK on success. A DB_Error object on failure.
+     *
+     * @link http://www.postgresql.org/docs/current/static/libpq.html#LIBPQ-CONNECT
+     */
+    function connect($dsn, $persistent = false)
+    {
+        if (!PEAR::loadExtension('pgsql')) {
+            return $this->raiseError(DB_ERROR_EXTENSION_NOT_FOUND);
+        }
+
+        $this->dsn = $dsn;
+        if ($dsn['dbsyntax']) {
+            $this->dbsyntax = $dsn['dbsyntax'];
+        }
+
+        $protocol = $dsn['protocol'] ? $dsn['protocol'] : 'tcp';
+
+        $params = array('');
+        if ($protocol == 'tcp') {
+            if ($dsn['hostspec']) {
+                $params[0] .= 'host=' . $dsn['hostspec'];
+            }
+            if ($dsn['port']) {
+                $params[0] .= ' port=' . $dsn['port'];
+            }
+        } elseif ($protocol == 'unix') {
+            // Allow for pg socket in non-standard locations.
+            if ($dsn['socket']) {
+                $params[0] .= 'host=' . $dsn['socket'];
+            }
+            if ($dsn['port']) {
+                $params[0] .= ' port=' . $dsn['port'];
+            }
+        }
+        if ($dsn['database']) {
+            $params[0] .= ' dbname=\'' . addslashes($dsn['database']) . '\'';
+        }
+        if ($dsn['username']) {
+            $params[0] .= ' user=\'' . addslashes($dsn['username']) . '\'';
+        }
+        if ($dsn['password']) {
+            $params[0] .= ' password=\'' . addslashes($dsn['password']) . '\'';
+        }
+        if (!empty($dsn['options'])) {
+            $params[0] .= ' options=' . $dsn['options'];
+        }
+        if (!empty($dsn['tty'])) {
+            $params[0] .= ' tty=' . $dsn['tty'];
+        }
+        if (!empty($dsn['connect_timeout'])) {
+            $params[0] .= ' connect_timeout=' . $dsn['connect_timeout'];
+        }
+        if (!empty($dsn['sslmode'])) {
+            $params[0] .= ' sslmode=' . $dsn['sslmode'];
+        }
+        if (!empty($dsn['service'])) {
+            $params[0] .= ' service=' . $dsn['service'];
+        }
+
+        if (isset($dsn['new_link'])
+            && ($dsn['new_link'] == 'true' || $dsn['new_link'] === true))
+        {
+            if (version_compare(phpversion(), '4.3.0', '>=')) {
+                $params[] = PGSQL_CONNECT_FORCE_NEW;
+            }
+        }
+
+        $connect_function = $persistent ? 'pg_pconnect' : 'pg_connect';
+
+        $ini = ini_get('track_errors');
+        $php_errormsg = '';
+        if ($ini) {
+            $this->connection = @call_user_func_array($connect_function,
+                                                      $params);
+        } else {
+            ini_set('track_errors', 1);
+            $this->connection = @call_user_func_array($connect_function,
+                                                      $params);
+            ini_set('track_errors', $ini);
+        }
+
+        if (!$this->connection) {
+            return $this->raiseError(DB_ERROR_CONNECT_FAILED,
+                                     null, null, null,
+                                     $php_errormsg);
+        }
+        return DB_OK;
+    }
+
+    // }}}
+    // {{{ disconnect()
+
+    /**
+     * Disconnects from the database server
+     *
+     * @return bool  TRUE on success, FALSE on failure
+     */
+    function disconnect()
+    {
+        $ret = @pg_close($this->connection);
+        $this->connection = null;
+        return $ret;
+    }
+
+    // }}}
+    // {{{ simpleQuery()
+
+    /**
+     * Sends a query to the database server
+     *
+     * @param string  the SQL query string
+     *
+     * @return mixed  + a PHP result resrouce for successful SELECT queries
+     *                + the DB_OK constant for other successful queries
+     *                + a DB_Error object on failure
+     */
+    function simpleQuery($query)
+    {
+        $ismanip = DB::isManip($query);
+        $this->last_query = $query;
+        $query = $this->modifyQuery($query);
+        if (!$this->autocommit && $ismanip) {
+            if ($this->transaction_opcount == 0) {
+                $result = @pg_exec($this->connection, 'begin;');
+                if (!$result) {
+                    return $this->pgsqlRaiseError();
+                }
+            }
+            $this->transaction_opcount++;
+        }
+        $result = @pg_exec($this->connection, $query);
+        if (!$result) {
+            return $this->pgsqlRaiseError();
+        }
+        // Determine which queries that should return data, and which
+        // should return an error code only.
+        if ($ismanip) {
+            $this->affected = @pg_affected_rows($result);
+            return DB_OK;
+        } elseif (preg_match('/^\s*\(*\s*(SELECT|EXPLAIN|SHOW)\s/si', $query)) {
+            /* PostgreSQL commands:
+               ABORT, ALTER, BEGIN, CLOSE, CLUSTER, COMMIT, COPY,
+               CREATE, DECLARE, DELETE, DROP TABLE, EXPLAIN, FETCH,
+               GRANT, INSERT, LISTEN, LOAD, LOCK, MOVE, NOTIFY, RESET,
+               REVOKE, ROLLBACK, SELECT, SELECT INTO, SET, SHOW,
+               UNLISTEN, UPDATE, VACUUM
+            */
+            $this->row[(int)$result] = 0; // reset the row counter.
+            $numrows = $this->numRows($result);
+            if (is_object($numrows)) {
+                return $numrows;
+            }
+            $this->_num_rows[(int)$result] = $numrows;
+            $this->affected = 0;
+            return $result;
+        } else {
+            $this->affected = 0;
+            return DB_OK;
+        }
+    }
+
+    // }}}
+    // {{{ nextResult()
+
+    /**
+     * Move the internal pgsql result pointer to the next available result
+     *
+     * @param a valid fbsql result resource
+     *
+     * @access public
+     *
+     * @return true if a result is available otherwise return false
+     */
+    function nextResult($result)
+    {
+        return false;
+    }
+
+    // }}}
+    // {{{ fetchInto()
+
+    /**
+     * Places a row from the result set into the given array
+     *
+     * Formating of the array and the data therein are configurable.
+     * See DB_result::fetchInto() for more information.
+     *
+     * This method is not meant to be called directly.  Use
+     * DB_result::fetchInto() instead.  It can't be declared "protected"
+     * because DB_result is a separate object.
+     *
+     * @param resource $result    the query result resource
+     * @param array    $arr       the referenced array to put the data in
+     * @param int      $fetchmode how the resulting array should be indexed
+     * @param int      $rownum    the row number to fetch (0 = first row)
+     *
+     * @return mixed  DB_OK on success, NULL when the end of a result set is
+     *                 reached or on failure
+     *
+     * @see DB_result::fetchInto()
+     */
+    function fetchInto($result, &$arr, $fetchmode, $rownum = null)
+    {
+        $result_int = (int)$result;
+        $rownum = ($rownum !== null) ? $rownum : $this->row[$result_int];
+        if ($rownum >= $this->_num_rows[$result_int]) {
+            return null;
+        }
+        if ($fetchmode & DB_FETCHMODE_ASSOC) {
+            $arr = @pg_fetch_array($result, $rownum, PGSQL_ASSOC);
+            if ($this->options['portability'] & DB_PORTABILITY_LOWERCASE && $arr) {
+                $arr = array_change_key_case($arr, CASE_LOWER);
+            }
+        } else {
+            $arr = @pg_fetch_row($result, $rownum);
+        }
+        if (!$arr) {
+            return null;
+        }
+        if ($this->options['portability'] & DB_PORTABILITY_RTRIM) {
+            $this->_rtrimArrayValues($arr);
+        }
+        if ($this->options['portability'] & DB_PORTABILITY_NULL_TO_EMPTY) {
+            $this->_convertNullArrayValuesToEmpty($arr);
+        }
+        $this->row[$result_int] = ++$rownum;
+        return DB_OK;
+    }
+
+    // }}}
+    // {{{ freeResult()
+
+    /**
+     * Deletes the result set and frees the memory occupied by the result set
+     *
+     * This method is not meant to be called directly.  Use
+     * DB_result::free() instead.  It can't be declared "protected"
+     * because DB_result is a separate object.
+     *
+     * @param resource $result  PHP's query result resource
+     *
+     * @return bool  TRUE on success, FALSE if $result is invalid
+     *
+     * @see DB_result::free()
+     */
+    function freeResult($result)
+    {
+        if (is_resource($result)) {
+            unset($this->row[(int)$result]);
+            unset($this->_num_rows[(int)$result]);
+            $this->affected = 0;
+            return @pg_freeresult($result);
+        }
+        return false;
+    }
+
+    // }}}
+    // {{{ quote()
+
+    /**
+     * @deprecated  Deprecated in release 1.6.0
+     * @internal
+     */
+    function quote($str)
+    {
+        return $this->quoteSmart($str);
+    }
+
+    // }}}
+    // {{{ quoteSmart()
+
+    /**
+     * Formats input so it can be safely used in a query
+     *
+     * @param mixed $in  the data to be formatted
+     *
+     * @return mixed  the formatted data.  The format depends on the input's
+     *                 PHP type:
+     *                 + null = the string <samp>NULL</samp>
+     *                 + boolean = string <samp>TRUE</samp> or <samp>FALSE</samp>
+     *                 + integer or double = the unquoted number
+     *                 + other (including strings and numeric strings) =
+     *                   the data escaped according to MySQL's settings
+     *                   then encapsulated between single quotes
+     *
+     * @see DB_common::quoteSmart()
+     * @since Method available since Release 1.6.0
+     */
+    function quoteSmart($in)
+    {
+        if (is_int($in) || is_double($in)) {
+            return $in;
+        } elseif (is_bool($in)) {
+            return $in ? 'TRUE' : 'FALSE';
+        } elseif (is_null($in)) {
+            return 'NULL';
+        } else {
+            return "'" . $this->escapeSimple($in) . "'";
+        }
+    }
+
+    // }}}
+    // {{{ escapeSimple()
+
+    /**
+     * Escapes a string according to the current DBMS's standards
+     *
+     * {@internal PostgreSQL treats a backslash as an escape character,
+     * so they are escaped as well.
+     *
+     * Not using pg_escape_string() yet because it requires PostgreSQL
+     * to be at version 7.2 or greater.}}
+     *
+     * @param string $str  the string to be escaped
+     *
+     * @return string  the escaped string
+     *
+     * @see DB_common::quoteSmart()
+     * @since Method available since Release 1.6.0
+     */
+    function escapeSimple($str)
+    {
+        return str_replace("'", "''", str_replace('\\', '\\\\', $str));
+    }
+
+    // }}}
+    // {{{ numCols()
+
+    /**
+     * Gets the number of columns in a result set
+     *
+     * This method is not meant to be called directly.  Use
+     * DB_result::numCols() instead.  It can't be declared "protected"
+     * because DB_result is a separate object.
+     *
+     * @param resource $result  PHP's query result resource
+     *
+     * @return int  the number of columns.  A DB_Error object on failure.
+     *
+     * @see DB_result::numCols()
+     */
+    function numCols($result)
+    {
+        $cols = @pg_numfields($result);
+        if (!$cols) {
+            return $this->pgsqlRaiseError();
+        }
+        return $cols;
+    }
+
+    // }}}
+    // {{{ numRows()
+
+    /**
+     * Gets the number of rows in a result set
+     *
+     * This method is not meant to be called directly.  Use
+     * DB_result::numRows() instead.  It can't be declared "protected"
+     * because DB_result is a separate object.
+     *
+     * @param resource $result  PHP's query result resource
+     *
+     * @return int  the number of rows.  A DB_Error object on failure.
+     *
+     * @see DB_result::numRows()
+     */
+    function numRows($result)
+    {
+        $rows = @pg_numrows($result);
+        if ($rows === null) {
+            return $this->pgsqlRaiseError();
+        }
+        return $rows;
+    }
+
+    // }}}
+    // {{{ autoCommit()
+
+    /**
+     * Enables or disables automatic commits
+     *
+     * @param bool $onoff  true turns it on, false turns it off
+     *
+     * @return int  DB_OK on success.  A DB_Error object if the driver
+     *               doesn't support auto-committing transactions.
+     */
+    function autoCommit($onoff = false)
+    {
+        // XXX if $this->transaction_opcount > 0, we should probably
+        // issue a warning here.
+        $this->autocommit = $onoff ? true : false;
+        return DB_OK;
+    }
+
+    // }}}
+    // {{{ commit()
+
+    /**
+     * Commits the current transaction
+     *
+     * @return int  DB_OK on success.  A DB_Error object on failure.
+     */
+    function commit()
+    {
+        if ($this->transaction_opcount > 0) {
+            // (disabled) hack to shut up error messages from libpq.a
+            //@fclose(@fopen("php://stderr", "w"));
+            $result = @pg_exec($this->connection, 'end;');
+            $this->transaction_opcount = 0;
+            if (!$result) {
+                return $this->pgsqlRaiseError();
+            }
+        }
+        return DB_OK;
+    }
+
+    // }}}
+    // {{{ rollback()
+
+    /**
+     * Reverts the current transaction
+     *
+     * @return int  DB_OK on success.  A DB_Error object on failure.
+     */
+    function rollback()
+    {
+        if ($this->transaction_opcount > 0) {
+            $result = @pg_exec($this->connection, 'abort;');
+            $this->transaction_opcount = 0;
+            if (!$result) {
+                return $this->pgsqlRaiseError();
+            }
+        }
+        return DB_OK;
+    }
+
+    // }}}
+    // {{{ affectedRows()
+
+    /**
+     * Determines the number of rows affected by a data maniuplation query
+     *
+     * 0 is returned for queries that don't manipulate data.
+     *
+     * @return int  the number of rows.  A DB_Error object on failure.
+     */
+    function affectedRows()
+    {
+        return $this->affected;
+    }
+
+    // }}}
+    // {{{ nextId()
+
+    /**
+     * Returns the next free id in a sequence
+     *
+     * @param string  $seq_name  name of the sequence
+     * @param boolean $ondemand  when true, the seqence is automatically
+     *                            created if it does not exist
+     *
+     * @return int  the next id number in the sequence.
+     *               A DB_Error object on failure.
+     *
+     * @see DB_common::nextID(), DB_common::getSequenceName(),
+     *      DB_pgsql::createSequence(), DB_pgsql::dropSequence()
+     */
+    function nextId($seq_name, $ondemand = true)
+    {
+        $seqname = $this->getSequenceName($seq_name);
+        $repeat = false;
+        do {
+            $this->pushErrorHandling(PEAR_ERROR_RETURN);
+            $result =& $this->query("SELECT NEXTVAL('${seqname}')");
+            $this->popErrorHandling();
+            if ($ondemand && DB::isError($result) &&
+                $result->getCode() == DB_ERROR_NOSUCHTABLE) {
+                $repeat = true;
+                $this->pushErrorHandling(PEAR_ERROR_RETURN);
+                $result = $this->createSequence($seq_name);
+                $this->popErrorHandling();
+                if (DB::isError($result)) {
+                    return $this->raiseError($result);
+                }
+            } else {
+                $repeat = false;
+            }
+        } while ($repeat);
+        if (DB::isError($result)) {
+            return $this->raiseError($result);
+        }
+        $arr = $result->fetchRow(DB_FETCHMODE_ORDERED);
+        $result->free();
+        return $arr[0];
+    }
+
+    // }}}
+    // {{{ createSequence()
+
+    /**
+     * Creates a new sequence
+     *
+     * @param string $seq_name  name of the new sequence
+     *
+     * @return int  DB_OK on success.  A DB_Error object on failure.
+     *
+     * @see DB_common::createSequence(), DB_common::getSequenceName(),
+     *      DB_pgsql::nextID(), DB_pgsql::dropSequence()
+     */
+    function createSequence($seq_name)
+    {
+        $seqname = $this->getSequenceName($seq_name);
+        $result = $this->query("CREATE SEQUENCE ${seqname}");
+        return $result;
+    }
+
+    // }}}
+    // {{{ dropSequence()
+
+    /**
+     * Deletes a sequence
+     *
+     * @param string $seq_name  name of the sequence to be deleted
+     *
+     * @return int  DB_OK on success.  A DB_Error object on failure.
+     *
+     * @see DB_common::dropSequence(), DB_common::getSequenceName(),
+     *      DB_pgsql::nextID(), DB_pgsql::createSequence()
+     */
+    function dropSequence($seq_name)
+    {
+        return $this->query('DROP SEQUENCE '
+                            . $this->getSequenceName($seq_name));
+    }
+
+    // }}}
+    // {{{ modifyLimitQuery()
+
+    /**
+     * Adds LIMIT clauses to a query string according to current DBMS standards
+     *
+     * @param string $query   the query to modify
+     * @param int    $from    the row to start to fetching (0 = the first row)
+     * @param int    $count   the numbers of rows to fetch
+     * @param mixed  $params  array, string or numeric data to be used in
+     *                         execution of the statement.  Quantity of items
+     *                         passed must match quantity of placeholders in
+     *                         query:  meaning 1 placeholder for non-array
+     *                         parameters or 1 placeholder per array element.
+     *
+     * @return string  the query string with LIMIT clauses added
+     *
+     * @access protected
+     */
+    function modifyLimitQuery($query, $from, $count, $params = array())
+    {
+        return "$query LIMIT $count OFFSET $from";
+    }
+
+    // }}}
+    // {{{ pgsqlRaiseError()
+
+    /**
+     * Produces a DB_Error object regarding the current problem
+     *
+     * @param int $errno  if the error is being manually raised pass a
+     *                     DB_ERROR* constant here.  If this isn't passed
+     *                     the error information gathered from the DBMS.
+     *
+     * @return object  the DB_Error object
+     *
+     * @see DB_common::raiseError(),
+     *      DB_pgsql::errorNative(), DB_pgsql::errorCode()
+     */
+    function pgsqlRaiseError($errno = null)
+    {
+        $native = $this->errorNative();
+        if ($errno === null) {
+            $errno = $this->errorCode($native);
+        }
+        return $this->raiseError($errno, null, null, null, $native);
+    }
+
+    // }}}
+    // {{{ errorNative()
+
+    /**
+     * Gets the DBMS' native error message produced by the last query
+     *
+     * {@internal Error messages are used instead of error codes 
+     * in order to support older versions of PostgreSQL.}}
+     *
+     * @return string  the DBMS' error message
+     */
+    function errorNative()
+    {
+        return @pg_errormessage($this->connection);
+    }
+
+    // }}}
+    // {{{ errorCode()
+
+    /**
+     * Determines PEAR::DB error code from the database's text error message.
+     *
+     * @param  string  $errormsg  error message returned from the database
+     * @return integer  an error number from a DB error constant
+     */
+    function errorCode($errormsg)
+    {
+        static $error_regexps;
+        if (!isset($error_regexps)) {
+            $error_regexps = array(
+                '/(relation|sequence|table).*does not exist|class .* not found/i'
+                    => DB_ERROR_NOSUCHTABLE,
+                '/index .* does not exist/'
+                    => DB_ERROR_NOT_FOUND,
+                '/column .* does not exist/i'
+                    => DB_ERROR_NOSUCHFIELD,
+                '/relation .* already exists/i'
+                    => DB_ERROR_ALREADY_EXISTS,
+                '/(divide|division) by zero$/i'
+                    => DB_ERROR_DIVZERO,
+                '/pg_atoi: error in .*: can\'t parse /i'
+                    => DB_ERROR_INVALID_NUMBER,
+                '/invalid input syntax for( type)? (integer|numeric)/i'
+                    => DB_ERROR_INVALID_NUMBER,
+                '/value .* is out of range for type \w*int/i'
+                    => DB_ERROR_INVALID_NUMBER,
+                '/integer out of range/i'
+                    => DB_ERROR_INVALID_NUMBER,
+                '/value too long for type character/i'
+                    => DB_ERROR_INVALID,
+                '/attribute .* not found|relation .* does not have attribute/i'
+                    => DB_ERROR_NOSUCHFIELD,
+                '/column .* specified in USING clause does not exist in (left|right) table/i'
+                    => DB_ERROR_NOSUCHFIELD,
+                '/parser: parse error at or near/i'
+                    => DB_ERROR_SYNTAX,
+                '/syntax error at/'
+                    => DB_ERROR_SYNTAX,
+                '/column reference .* is ambiguous/i'
+                    => DB_ERROR_SYNTAX,
+                '/permission denied/'
+                    => DB_ERROR_ACCESS_VIOLATION,
+                '/violates not-null constraint/'
+                    => DB_ERROR_CONSTRAINT_NOT_NULL,
+                '/violates [\w ]+ constraint/'
+                    => DB_ERROR_CONSTRAINT,
+                '/referential integrity violation/'
+                    => DB_ERROR_CONSTRAINT,
+                '/more expressions than target columns/i'
+                    => DB_ERROR_VALUE_COUNT_ON_ROW,
+            );
+        }
+        foreach ($error_regexps as $regexp => $code) {
+            if (preg_match($regexp, $errormsg)) {
+                return $code;
+            }
+        }
+        // Fall back to DB_ERROR if there was no mapping.
+        return DB_ERROR;
+    }
+
+    // }}}
+    // {{{ tableInfo()
+
+    /**
+     * Returns information about a table or a result set
+     *
+     * NOTE: only supports 'table' and 'flags' if <var>$result</var>
+     * is a table name.
+     *
+     * @param object|string  $result  DB_result object from a query or a
+     *                                 string containing the name of a table.
+     *                                 While this also accepts a query result
+     *                                 resource identifier, this behavior is
+     *                                 deprecated.
+     * @param int            $mode    a valid tableInfo mode
+     *
+     * @return array  an associative array with the information requested.
+     *                 A DB_Error object on failure.
+     *
+     * @see DB_common::tableInfo()
+     */
+    function tableInfo($result, $mode = null)
+    {
+        if (is_string($result)) {
+            /*
+             * Probably received a table name.
+             * Create a result resource identifier.
+             */
+            $id = @pg_exec($this->connection, "SELECT * FROM $result LIMIT 0");
+            $got_string = true;
+        } elseif (isset($result->result)) {
+            /*
+             * Probably received a result object.
+             * Extract the result resource identifier.
+             */
+            $id = $result->result;
+            $got_string = false;
+        } else {
+            /*
+             * Probably received a result resource identifier.
+             * Copy it.
+             * Deprecated.  Here for compatibility only.
+             */
+            $id = $result;
+            $got_string = false;
+        }
+
+        if (!is_resource($id)) {
+            return $this->pgsqlRaiseError(DB_ERROR_NEED_MORE_DATA);
+        }
+
+        if ($this->options['portability'] & DB_PORTABILITY_LOWERCASE) {
+            $case_func = 'strtolower';
+        } else {
+            $case_func = 'strval';
+        }
+
+        $count = @pg_numfields($id);
+        $res   = array();
+
+        if ($mode) {
+            $res['num_fields'] = $count;
+        }
+
+        for ($i = 0; $i < $count; $i++) {
+            $res[$i] = array(
+                'table' => $got_string ? $case_func($result) : '',
+                'name'  => $case_func(@pg_fieldname($id, $i)),
+                'type'  => @pg_fieldtype($id, $i),
+                'len'   => @pg_fieldsize($id, $i),
+                'flags' => $got_string
+                           ? $this->_pgFieldFlags($id, $i, $result)
+                           : '',
+            );
+            if ($mode & DB_TABLEINFO_ORDER) {
+                $res['order'][$res[$i]['name']] = $i;
+            }
+            if ($mode & DB_TABLEINFO_ORDERTABLE) {
+                $res['ordertable'][$res[$i]['table']][$res[$i]['name']] = $i;
+            }
+        }
+
+        // free the result only if we were called on a table
+        if ($got_string) {
+            @pg_freeresult($id);
+        }
+        return $res;
+    }
+
+    // }}}
+    // {{{ _pgFieldFlags()
+
+    /**
+     * Get a column's flags
+     *
+     * Supports "not_null", "default_value", "primary_key", "unique_key"
+     * and "multiple_key".  The default value is passed through
+     * rawurlencode() in case there are spaces in it.
+     *
+     * @param int $resource   the PostgreSQL result identifier
+     * @param int $num_field  the field number
+     *
+     * @return string  the flags
+     *
+     * @access private
+     */
+    function _pgFieldFlags($resource, $num_field, $table_name)
+    {
+        $field_name = @pg_fieldname($resource, $num_field);
+
+        $result = @pg_exec($this->connection, "SELECT f.attnotnull, f.atthasdef
+                                FROM pg_attribute f, pg_class tab, pg_type typ
+                                WHERE tab.relname = typ.typname
+                                AND typ.typrelid = f.attrelid
+                                AND f.attname = '$field_name'
+                                AND tab.relname = '$table_name'");
+        if (@pg_numrows($result) > 0) {
+            $row = @pg_fetch_row($result, 0);
+            $flags  = ($row[0] == 't') ? 'not_null ' : '';
+
+            if ($row[1] == 't') {
+                $result = @pg_exec($this->connection, "SELECT a.adsrc
+                                    FROM pg_attribute f, pg_class tab, pg_type typ, pg_attrdef a
+                                    WHERE tab.relname = typ.typname AND typ.typrelid = f.attrelid
+                                    AND f.attrelid = a.adrelid AND f.attname = '$field_name'
+                                    AND tab.relname = '$table_name' AND f.attnum = a.adnum");
+                $row = @pg_fetch_row($result, 0);
+                $num = preg_replace("/'(.*)'::\w+/", "\\1", $row[0]);
+                $flags .= 'default_' . rawurlencode($num) . ' ';
+            }
+        } else {
+            $flags = '';
+        }
+        $result = @pg_exec($this->connection, "SELECT i.indisunique, i.indisprimary, i.indkey
+                                FROM pg_attribute f, pg_class tab, pg_type typ, pg_index i
+                                WHERE tab.relname = typ.typname
+                                AND typ.typrelid = f.attrelid
+                                AND f.attrelid = i.indrelid
+                                AND f.attname = '$field_name'
+                                AND tab.relname = '$table_name'");
+        $count = @pg_numrows($result);
+
+        for ($i = 0; $i < $count ; $i++) {
+            $row = @pg_fetch_row($result, $i);
+            $keys = explode(' ', $row[2]);
+
+            if (in_array($num_field + 1, $keys)) {
+                $flags .= ($row[0] == 't' && $row[1] == 'f') ? 'unique_key ' : '';
+                $flags .= ($row[1] == 't') ? 'primary_key ' : '';
+                if (count($keys) > 1)
+                    $flags .= 'multiple_key ';
+            }
+        }
+
+        return trim($flags);
+    }
+
+    // }}}
+    // {{{ getSpecialQuery()
+
+    /**
+     * Obtains the query string needed for listing a given type of objects
+     *
+     * @param string $type  the kind of objects you want to retrieve
+     *
+     * @return string  the SQL query string or null if the driver doesn't
+     *                  support the object type requested
+     *
+     * @access protected
+     * @see DB_common::getListOf()
+     */
+    function getSpecialQuery($type)
+    {
+        switch ($type) {
+            case 'tables':
+                return 'SELECT c.relname AS "Name"'
+                        . ' FROM pg_class c, pg_user u'
+                        . ' WHERE c.relowner = u.usesysid'
+                        . " AND c.relkind = 'r'"
+                        . ' AND NOT EXISTS'
+                        . ' (SELECT 1 FROM pg_views'
+                        . '  WHERE viewname = c.relname)'
+                        . " AND c.relname !~ '^(pg_|sql_)'"
+                        . ' UNION'
+                        . ' SELECT c.relname AS "Name"'
+                        . ' FROM pg_class c'
+                        . " WHERE c.relkind = 'r'"
+                        . ' AND NOT EXISTS'
+                        . ' (SELECT 1 FROM pg_views'
+                        . '  WHERE viewname = c.relname)'
+                        . ' AND NOT EXISTS'
+                        . ' (SELECT 1 FROM pg_user'
+                        . '  WHERE usesysid = c.relowner)'
+                        . " AND c.relname !~ '^pg_'";
+            case 'schema.tables':
+                return "SELECT schemaname || '.' || tablename"
+                        . ' AS "Name"'
+                        . ' FROM pg_catalog.pg_tables'
+                        . ' WHERE schemaname NOT IN'
+                        . " ('pg_catalog', 'information_schema', 'pg_toast')";
+            case 'views':
+                // Table cols: viewname | viewowner | definition
+                return 'SELECT viewname from pg_views WHERE schemaname'
+                        . " NOT IN ('information_schema', 'pg_catalog')";
+            case 'users':
+                // cols: usename |usesysid|usecreatedb|usetrace|usesuper|usecatupd|passwd  |valuntil
+                return 'SELECT usename FROM pg_user';
+            case 'databases':
+                return 'SELECT datname FROM pg_database';
+            case 'functions':
+            case 'procedures':
+                return 'SELECT proname FROM pg_proc WHERE proowner <> 1';
+            default:
+                return null;
+        }
+    }
+
+    // }}}
+
+}
+
+/*
+ * Local variables:
+ * tab-width: 4
+ * c-basic-offset: 4
+ * End:
+ */
+
+?>