<?php
/***************************************************************************
 *                                 mssql.php
 *                            -------------------
 *   begin                : Saturday, Feb 13, 2001
 *   copyright            : (C) 2001 The phpBB Group
 *   email                : supportphpbb.com
 *
 *   $Id$
 *
 ***************************************************************************/

/***************************************************************************
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 ***************************************************************************/

if(!defined("SQL_LAYER"))
{

define("SQL_LAYER","mssql");

class sql_db
{

	var $db_connect_id;
	var $query_result;
	var $in_transaction = 0;
	var $transaction_name;
	var $query_limit_offset;
	var $query_limit_numrows;
	var $query_limit_success;
	var $next_id;
	var $row;
	var $num_queries = 0;

	//
	// Constructor
	//
	function sql_db($sqlserver, $sqluser, $sqlpassword, $database, $persistency = true)
	{

		$this->persistency = $persistency;
		$this->user = $sqluser;
		$this->password = $sqlpassword;
		$this->server = $sqlserver;
		$this->dbname = $database;

		if($this->persistency)
		{
			$this->db_connect_id = @mssql_pconnect($this->server, $this->user, $this->password);
		}
		else
		{
			$this->db_connect_id = @mssql_connect($this->server, $this->user, $this->password);
		}

		if($this->db_connect_id)
		{
			if($this->dbname != "")
			{
				$dbselect = @mssql_select_db($this->dbname, $this->db_connect_id);
				if(!$dbselect)
				{
					@mssql_close($this->db_connect_id);
					return false;
				}
			}
		}
		return $this->db_connect_id;
	}

	//
	// Other base methods
	//
	function sql_close()
	{
		if($this->db_connect_id)
		{
			$result = @mssql_close($this->db_connect_id);
			return $result;
		}
		else
		{
			return false;
		}
	}


	//
	// Query method
	//
	function sql_query($query = "", $transaction = FALSE)
	{
		//
		// Remove any pre-existing queries
		//
		unset($this->query_result);
		unset($this->row);

		if($query != "")
		{
			$this->num_queries++;
			if($transaction == BEGIN_TRANSACTION)
			{
				$result = mssql_query("BEGIN TRANSACTION", $this->db_connect_id);
				if(!$result)
				{
					return false;
				}
				$this->in_transaction = TRUE;
			}

			//
			// Does query contain any LIMIT code? If so pull out relevant start and num_results
			// This isn't terribly easy with MSSQL, whatever you do will potentially impact
			// performance compared to an 'in-built' limit
			//
			// Another issue is the 'lack' of a returned true value when a query is valid but has
			// no result set (as with all the other DB interfaces). It seems though that it's 
			// 'fair' to say that if a query returns a false result (ie. no resource id) then the
			// SQL was valid but had no result set. If the query returns nothing but the rowcount
			// returns something then there's a problem. This may well be a false assumption though 
			// ... needs checking under Windows itself.
			//
			if(eregi("LIMIT", $query))
			{
				preg_match("/^(.*)LIMIT ([0-9]+)[, ]*([0-9]+)*/s", $query, $limits);

				$query = $limits[1];
				if($limits[3])
				{
					$row_offset = $limits[2];
					$num_rows = $limits[3];
				}
				else
				{
					$row_offset = 0;
					$num_rows = $limits[2];
				}
	
				@mssql_query("SET ROWCOUNT ".($row_offset + $num_rows));

				$this->query_result = @mssql_query($query, $this->db_connect_id);

				@mssql_query("SET ROWCOUNT 0");

				$this->query_limit_success[$this->query_result] = true;

				$this->query_limit_offset[$this->query_result] = -1;
				$this->query_limit_numrows[$this->query_result] = $num_rows;

				if($this->query_result && $row_offset > 0)
				{
					$result = @mssql_data_seek($this->query_result, $row_offset);
					if(!$result)
					{
						$this->query_limit_success[$query_id] = false;
					}
					$this->query_limit_offset[$this->query_result] = $row_offset;
				}
			}
			else if(eregi("^INSERT ", $query))
			{
				$this->query_result = @mssql_query($query, $this->db_connect_id);

				if($this->query_result)
				{
					$next_id_query = @mssql_query("SELECT @@IDENTITY AS this_id");
					$this->next_id[$this->query_result] = $this->sql_fetchfield("this_id", -1, $next_id_query);
				}
				else
				{
					if($this->in_transaction)
					{
						mssql_query("ROLLBACK", $this->db_connect_id);
						$this->in_transaction = FALSE;
					}
					return false;
				}

				$this->query_limit_offset[$this->query_result] = -1;
				$this->query_limit_numrows[$this->query_result] = -1;
			}
			else 
			{
				if(eregi("SELECT", $query))
				{
					$this->query_result = @mssql_query($query, $this->db_connect_id);
				}
				else
				{
					$this->query_result = @mssql_query($query, $this->db_connect_id);
					if($this->query_result)
					{
						$this->query_result = uniqid(rand());
					}
				}

				if($this->query_result)
				{
					$affected_query = @mssql_query("SELECT @@ROWCOUNT AS this_count");

					$this->affected_rows[$this->query_result] = $this->sql_fetchfield("this_count", -1, $affected_query);

					$this->query_limit_offset[$this->query_result] = -1;
					$this->query_limit_numrows[$this->query_result] = -1;
				}
				else
				{
					if($this->in_transaction)
					{
						mssql_query("ROLLBACK", $this->db_connect_id);
						$this->in_transaction = FALSE;
					}
					return false;
				}
			}

			if($transaction == END_TRANSACTION)
			{
				$result = mssql_query("COMMIT", $this->db_connect_id);
			}

			return $this->query_result;
		}
		else
		{
			if($transaction == END_TRANSACTION)
			{
				$result = mssql_query("COMMIT", $this->db_connect_id);
				$this->in_transaction = FALSE;
			}

			return false;
		}
	}

	//
	// Other query methods
	//
	function sql_numrows($query_id = 0)
	{
		if(!$query_id)
		{
			$query_id = $this->query_result;
		}
		if($query_id)
		{
			if($this->query_limit_offset[$query_id] > 0)
			{
				$result = @mssql_num_rows($query_id) - $this->query_limit_offset[$query_id];
			}
			else
			{ 
				$result = @mssql_num_rows($query_id);
			}
			return $result;
		}
		else
		{
			return false;
		}
	}
	function sql_affectedrows($query_id = 0)
	{
		if(!$query_id)
		{
			$query_id = $this->query_result;
		}
		if($query_id)
		{
			return $this->affected_rows[$query_id];
		}
		else
		{
			return false;
		}
	}
	function sql_numfields($query_id = 0)
	{
		if(!$query_id)
		{
			$query_id = $this->query_result;
		}
		if($query_id)
		{
			$result = @mssql_num_fields($query_id);
			return $result;
		}
		else
		{
			return false;
		}
	}
	function sql_fieldname($offset, $query_id = 0)
	{
		if(!$query_id)
		{
			$query_id = $this->query_result;
		}
		if($query_id)
		{
			$result = @mssql_field_name($query_id, $offset);
			return $result;
		}
		else
		{
			return false;
		}
	}
	function sql_fieldtype($offset, $query_id = 0)
	{
		if(!$query_id)
		{
			$query_id = $this->query_result;
		}
		if($query_id)
		{
			$result = @mssql_field_type($query_id, $offset);
			return $result;
		}
		else
		{
			return false;
		}
	}
	function sql_fetchrow($query_id = 0)
	{
		if(!$query_id)
		{
			$query_id = $this->query_result;
		}
		if($query_id)
		{
	
			if($this->query_limit_offset[$query_id] > 0)
			{
				if($this->query_limit_success)
				{
					$this->row = @mssql_fetch_array($query_id);
					return $this->row;
				}
				else
				{
					return false;
				}
			}
			else
			{
				$this->row = @mssql_fetch_array($query_id);
				return $this->row;
			}
		}
		else
		{
			return false;
		}
	}
	function sql_fetchrowset($query_id = 0)
	{
		if(!$query_id)
		{
			$query_id = $this->query_result;
		}
		if($query_id)
		{
			if($this->query_limit_success[$query_id])
			{
				empty($this->rowset);
				while($this->rowset = @mssql_fetch_array($query_id))
				{
					$result[] = $this->rowset;
				}
			}
			else if($this->query_limit_numrows[$query_id] == -1)
			{
				empty($this->rowset);
				while($this->rowset = @mssql_fetch_array($query_id))
				{
					$result[] = $this->rowset;
				}
			}
			else
			{
				$result = false;
			}
			return $result;
		}
		else
		{
			return false;
		}
	}
	function sql_fetchfield($field, $row = -1, $query_id)
	{
		if(!$query_id)
		{
			$query_id = $this->query_result;
		}
		if($query_id)
		{
			if($row != -1)
			{
				if($this->query_limit_offset[$query_id] > 0)
				{
					if($this->query_limit_offset[$query_id] > 0 && $this->query_limit_success)
					{
						$result = @mssql_result($this->query_result, ($this->query_limit_offset[$query_id] + $row), $field);
					}
					else
					{
						return false;
					}
				}
				else
				{
					$result = @mssql_result($this->query_result, $row, $field);
				}
			}
			else
			{
				if(empty($this->row))
				{
					$this->row = @mssql_fetch_array($query_id);
					$result = $this->row[$field];
				}
			}
			return $result;
		}
		else
		{
			return false;
		}
	}
	function sql_rowseek($rownum, $query_id = 0)
	{
		if(!$query_id)
		{
			$query_id = $this->query_result;
		}
		if($query_id)
		{
			if($this->query_limit_offset[$query_id] > 0)
			{
				$result = @mssql_data_seek($query_id, ($this->query_limit_offset[$query_id] + $rownum));
			}
			else
			{
				$result = @mssql_data_seek($query_id, $rownum);
			}
			return $result;
		}
		else
		{
			return false;
		}
	}
	function sql_nextid($query_id = 0)
	{
		if(!$query_id)
		{
			$query_id = $this->query_result;
		}
		if($query_id)
		{
			return $this->next_id[$query_id];
		}
		else
		{
			return false;
		}
	}
	function sql_freeresult($query_id = 0)
	{
		if(!$query_id)
		{
			$query_id = $this->query_result;
		}
		if($query_id)
		{
			$result = @mssql_free_result($query_id);
			return $result;
		}
		else
		{
			return false;
		}
	}
	function sql_error($query_id = 0)
	{
		$result[message] = @mssql_get_last_message();
		return $result;
	}

} // class sql_db

} // if ... define

?>