<?php // vim:ts=4:sw=4:noet

if (!function_exists('sybase_connect'))
	trigger_error('sybase_* functions not defined. Install php*-sybase.', E_USER_ERROR);
require_once(dirname(__FILE__) . '/KjwSql.php');
require_once(dirname(__FILE__) . '/KjwArrayResultSet.php');
require_once(dirname(__FILE__) . '/KjwMsResultSet.php');

/** @ingroup sql
 *
 * KjwMsSql is the mssql implementation of the KjwSql abstract class.
 * Uses the KJW_DIE_ON_TRANSIENT_ERROR define.
 */
class KjwMsSql extends KjwSql {
	var $_dbconn;		/**< Database resource */
	var $_insertId;		/**< Insert ID / Identity ID of last query (insert/update). */
	var $_affectedRows;	/**< Count of rows affected with last query (insert/update). */

	/**
	 * Construct a KjwMsSql object.
     *
	 * @param $hostname Server name or IP.
	 * @param $portnum Port number of 0 if default.
	 * @param $username User name.
	 * @param $password Password.
	 * @param $database Database name.
	 */
	function KjwMsSql($hostname, $portnum, $username, $password, $database) {
		parent::KjwSql('mssql', $hostname, $portnum ? $portnum : 1433, $username, $password, $database);
		$this->_dbconn = null;
		$this->_insertId = $this->_affectedRows = null;
	}

	/* [INHERITED DOCS] */
	function destroy() {
		$this->disconnect();
		parent::destroy();
	}
	
	/* [INHERITED DOCS] */
	function connect() {
		if ($this->_dbconn)
			return true;
		$this->_dbconn = false; // If we fail, we'll be false instead of null.
		if (($res = @sybase_connect($this->_hostname . ':' . $this->_portnum, $this->_username, $this->_password, 'KjwApp')) == false) {
			global $kjw_suppressed_error;
			$this->setError("Connection to database (temporarily) failed; host={$this->_hostname}:{$this->_portnum}, "
					. "user={$this->_username}, db={$this->_database}. "
					. $kjw_suppressed_error);
			if (KJW_DIE_ON_TRANSIENT_ERROR)
				$this->croak('Database Connection Failure', $this->getError());
			return false;
		}
		if (@sybase_select_db($this->nameQuote($this->_database), $res) == false) {
			$this->setError(sybase_get_last_message());
			if (KJW_DIE_ON_TRANSIENT_ERROR)
				$this->croak('Database Connection Failure', $this->getError());
			@sybase_close($res);
			return false;
		}
		$this->_dbconn = $res;
		return true;
	}

	/* [INHERITED DOCS] */
	function disconnect() {
		if (!$this->_dbconn)
			return true;
		if ($ret = @sybase_close($this->_dbconn))
			$this->_dbconn = null;
		return $ret;
	}
	
	/* [INHERITED DOCS] */
	function beginWork() {
		// BEGIN WORK does not work on MsSql.
		return $this->execute('BEGIN TRANSACTION');
	}

	/* [INHERITED DOCS] */
	function execute($query) {
		if ($this->_dbconn === null)
			$this->connect(); // Auto-connect once.
		$this->_setLastQuery($query);
		$is_select = $is_insert_update = false;

		// As seen in bugs: http://bugs.php.net/bug.php?id=36639 and http://bugs.php.net/bug.php?id=42544
		// All MSSQL links started with the same arguments, share the same link.
		// Therefore we have to reselect the database.
		if (@sybase_select_db($this->nameQuote($this->_database), $this->_dbconn) === false)
			$this->croak('Database Data Transfer Failure', 'Second sybase_select_db failed. Error in bugfix. Dying.');

		// If query is an insert/update, we add code to select @@IDENTITY/@@ROWCOUNT.
		if (preg_match('!^\s*(insert|update)\s+!i', $query)) {
			$this->_insertId = $this->_affectedRows = null;
			$is_insert_update = true;
			// Some databases require a BEGIN TRANSACTION around the @@ROWCOUNT as well... haven't found out why.
			$query = "BEGIN TRANSACTION ; $query ; SELECT @@ROWCOUNT AS rc, @@IDENTITY AS id ; COMMIT";
		} elseif (preg_match('!^\s*select\s+!i', $query)) {
			$this->_insertId = $this->_affectedRows = null;
			$is_select = true;
		}

		// Run it.
		if (($res = @sybase_query($query, $this->_dbconn)) === false) {
			$errmsg = @sybase_get_last_message();
			if (($res = sybase_query('SELECT @@ERROR AS error', $this->_dbconn)) !== false) {
				$row = sybase_fetch_assoc($res);
				$errmsg .= ' [' . array_shift($row) . ']';
			}
			$errmsg .= ' Query was: ' . $this->_getLastQuery();
			$this->croak('Database Data Transfer Failure', "sybase_query failed: $errmsg");
		}

		if (is_bool($res)) {
			// Ms Sql returns true instead of an empty result on empty select.
			if ($is_select)
				return new KjwArrayResultSet(array());
			return true;
		} elseif ($is_insert_update && sybase_num_rows($res) == 1) {
			$row = sybase_fetch_assoc($res);
			sybase_free_result($res);
			$this->_affectedRows = array_shift($row);
			if (is_integer($this->_affectedRows))
				$this->_affectedRows = (int)$this->_affectedRows;
			$this->_insertId = array_shift($row);
			if (is_integer($this->_insertId))
				$this->_insertId = (int)$this->_insertId;
			return true;
		}
		return new KjwMsResultSet($res);
	}

	/* [INHERITED DOCS] */
	/* NB: Can't find docs on exact escaping. We'll do s/'/''/g and s/\0//g. */
	function safeQuote($mixed) {
		if(is_string($mixed))
			return "N'" . str_replace("'", "''", str_replace("\x00", "", $mixed)) . "'";
		$ret = parent::safeQuote($mixed);
		// We usually use UTF8.. this is converted to UCS2 if we use NVARCHARs.
		// We do need to give the N'string' instead of 'string'.
		return $ret[0] == "'" ? 'N' . $ret : $ret;
	}

	/* [INHERITED DOCS] */
	function nameQuote($string) {
		return '[' . str_replace(']', ']]', preg_replace("/[\x01-\x1f]/", '',
				str_replace("\x00", '', $string))) . ']';
	}

	/* [INHERITED DOCS] */
	function affectedRows() {
		// sybase_affected_rows($this->_dbconn) does *not* work with MsSql or something..
		// SELECT @@ROWCOUNT *only* works within the same execute statement
		//if ($this->_affectedRows === null)
		//	$this->_affectedRows = $this->selectAtom('@@ROWCOUNT');
		return $this->_affectedRows;
	}
	
	/* [INHERITED DOCS] */
	function insertId() {
		//return $this->selectAtom('@@IDENTITY');
		return $this->_insertId;
	}	
}

?>