<?php





/**

* Database platform implementation for MSSQL.

* @author Michal Palma <palmic at email dot cz>



* @package DbControl

* @version 1.5



* @date 2006-01-11

*/

class DbMssql extends DbPlatform

{



    //== Attributes ======================================================================

    //== constructors ====================================================================



    public function DbMssql(DbParametersMessenger $dbParametersMessenger, DbStateHandler $dbStateHandler) {

        if (!in_array("mssql", get_loaded_extensions())) {

            throw new DbControlException("Your PHP configuration does not support MSSQL extension. Check php.ini.");

        }

        $this->dbParametersMessenger = $dbParametersMessenger;

        $this->dbStateHandler = $dbStateHandler;

    }



    //== destructors =====================================================================



    public function __destruct() {

        if ($this->activeTransaction) {

            if ($this->autoCommit) {

                $this->transactionCommit();

            }

            else {

                $this->transactionRollback();

            }

        }

        @mssql_close($this->connection);

    }





    //== public functions ================================================================



    public function fetchAssoc($result) {

        if (!is_resource($result)) {

            throw new DbControlException("Ilegal parameter result. Must be valid result resource.");

        }

        else {

            return @mssql_fetch_assoc($result);

        }

    }



    public function getLastId() {

        try {

            $result = $this->query("SELECT LAST_INSERT_ID()");

            $id = mssql_result($result, 0, 0);

        }

        catch (Exception $e) {

            throw new DbControlException("Error in trying to acquire Last inserted id.\n" . $e->getMessage(), $e->getCode());

        }

        return $id;

    }



    public function selectDb(/*string*/ $dbName) {

        if (!is_string($dbName)) {

            throw new DbControlException("Ilegal parameter dbName. Must be string.");

        }

        try {

            $this->query("USE ". $dbName);

        }

        catch (Exception $e) {

            throw $e;

        }

    }



    public function query(/*string*/ $query) {

        if (!is_string($query)) {

            throw new DbControlException("Ilegal parameter query. Must be string.");

        }

        try {
        	$result = @mssql_query($query, $this->getConnection());

			// v pripade vkladani musime zajistit povoleni vlozeni zaznamu s definovanym Primary key
            if (!$result) {
	            if (eregi("^INSERT INTO (\[[[:alnum:]_]+\]) ", $query, $regs)) {
					@mssql_query("SET IDENTITY_INSERT ". $regs[1] ." ON", $this->getConnection());
					$result	= @mssql_query($query, $this->getConnection());
				}
            }
            if (!$result) {

                $this->throwMssqlException("SQL query caused Error. Query: ". $query);

            }

        }

        catch (Exception $e) {

            throw $e;

        }



        return $result;

    }



    public function getNumRows(/*resource*/ $result) {

        if (!is_resource($result)) {

            throw new DbControlException("Ilegal parameter result. Must be valid result resource.");

        }

        else {

            return @mssql_num_rows($result);

        }

    }



    public function getColnames(/*resource*/ $result) {

        if (!is_resource($result)) {

            throw new DbControlException("Ilegal parameter result. Must be valid result resource.");

        }

        if (!$numFields = @mssql_num_fields($result)) {

            throw new DbControlException("No Column in result.");

        }

        for ($i = 0; $i < $numFields; $i++) {

            if (!$colname = @mssql_field_name($result, $i)) {

                $this->throwMssqlException("Colnames reading error.");

            }

            $colnames[$i] = $colname;

        }

        return $colnames;

    }



    public function transactionStart(/*boolean*/ $autoCommit) {

        if (!is_bool($autoCommit)) {

            throw new DbControlException("Ilegal parameter autoCommit. Must be boolean.");

        }

        if (!$this->activeTransaction) {

            try {

                $this->query("BEGIN TRANSACTION");

            }

            catch (Exception $e) {

                throw $e;

            }

            $this->autoCommit = $autoCommit;

            $this->activeTransaction = true;

        }

        else {

            throw new DbControlException("Multiple transactions are not supported.");

        }

    }



    public function transactionCommit() {

        if ($this->activeTransaction) {

            try {

                $this->query("COMMIT");

            }

            catch (Exception $e) {

                throw $e;

            }

            $this->activeTransaction = false;

        }

        else {

            throw new DbControlException("No transaction active.");

        }

    }



    public function transactionRollback() {

        if ($this->activeTransaction) {

            try {

                $this->query("ROLLBACK");

            }

            catch (Exception $e) {

                throw $e;

            }

            $this->activeTransaction = false;

        }

        else {

            throw new DbControlException("No transaction active.");

        }

    }





    //== protected functions =============================================================



    protected function connect() {

        if(!is_resource($this->connection)) {

			
        	$hostString = $this->dbParametersMessenger->loginHost;
			

            // we are not using port value in MSSQL connection - there was problems with that.

//            if (strlen($this->dbParametersMessenger->port) > 0) {

//                $hostString = $this->dbParametersMessenger->loginHost .":". $this->dbParametersMessenger->port;

//            }

//            else {

//                $hostString = $this->dbParametersMessenger->loginHost;

//            }

			for ($i = 0; $i < 50; $i++) {

            	$this->connection = @mssql_pconnect($hostString, $this->dbParametersMessenger->loginName, $this->dbParametersMessenger->loginPassword);

				if (is_resource($this->connection)) break;

				sleep(0.2);

			}

            if (!is_resource($this->connection)) {

                throw new DbControlException("Cant connect to database Mssql.\nhost = ". $this->dbParametersMessenger->loginHost, -1);

            }


            //setting default task database schema - if defined 
            # Caution: Using $this->query() may rewrite query that is waiting for execute
            if (strlen($schema = $this->dbParametersMessenger->schema) > 0) {            	
	            if (!@mssql_query("USE $schema;", $this->connection)) {
	                $this->throwMssqlException("Cannot select default database schema '$schema'.");
	            }
            }
        }

    }



    /**

    * getter for connection

    * @return valid connection resource

    */

    protected function getConnection() {

        try {

            $this->connect();

        }

        catch (Exception $e) {

            throw $e;

        }

        return $this->connection;

    }



    /**

    * Throws Exception with Mssql error infos

    * @return void

    */

    protected function throwMssqlException(/*string*/ $addToMessage = "") {

        if (is_string($addToMessage)) {

            $message = $addToMessage ."\n". @mssql_get_last_message();

        }

        else {

            $message = @mssql_get_last_message();

        }

        throw new DbControlException($message);

    }

}



?>