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18. Appendix F PostgreSQL Database Wrapper Examples

Submitted by: Joe Thong [email protected] Site URL: http://phpdb.linuxbox.com

Description: A PHP database wrapper for various database servers with a powerful Recordset for result data manipulation. Database results are flushed automatically by phpDB.

To get this file, in the web-browser, save this file as 'Text' type as phpDB-postgresql.lib


<?php
/*
Name: phpDB PostgreSQL module
Version: 1.02bR6
Description: A PHP database wrapper for various database 
        servers with a powerful recordset for result data 
        manipulation.  Database results are flushed 
        automatically by phpDB.  
*/

/* define this module, to prevent double class declaration.     */
if (!defined("_PHPDB_ABSTRACT_LAYER")) {
        define("_PHPDB_ABSTRACT_LAYER", 1 );
}
else
        return;

//---------------------------------------
         Class Name: phpDB
//---------------------------------------
class phpDB 
{
        /*      public variables        */
        var $version = '1.02bR6'; // Version number of phpDB
        // This variable keeps what database type is going to 
        // be used.  Current supported database server are 
        // MySQL, MSQL, SQL Server, and Sybase
        var $databaseType = '';
        // Specifies which database is going to be used
        var $databaseName = ''; 
        // The hostname of the database server, port 
        // number is optional.  e.g: "db.devNation.com"
        var $hostname = '';     
        var $username = ''; // used to connect to the database server
        var $password = ''; // Password for the username

        // Private variables ------ starts with underscore
        // An array of executed querys. For results cleanup purposes.
        var $_queryIDList = array();
        // The returned link identifier whenever a 
        // successful database connection is made
        var $_connectionID      = -1;   
        // A variable which was used to keep the returned 
        // last error message.  The value will then returned 
        // by the errorMsg() function
        var $_errorMsg = '';
                                                
        // This variable keeps the last created result 
        // link identifier
        var $_queryID = -1;     
        // A boolean variable to state whether its a persistent
        // connection or normal connection
        var     $_isPersistentConnection = false;
        // Holds the newly created result object, 
        // returned via the execute() method
        var $_tempResultObj = '';       

        // A constructor function for the phpDB object.  
        // When initializing, specify the dbType i.e: "mysql",
        // "msql", "postgresql", "mssql", and "sybase"
        function phpDB($dbType = "postgresql") 
        {
                switch ($dbType) {
                        case "mysql":
                        case "msql":
                        case "postgresql":
                        case "mssql":
                        case "sybase":                                          
                        case "informix":                                                
                                $this->databaseType = $dbType;
                                break;
                        default:
                                return false;
                }                       
        }
        
        // Returns: A positive link identifier on success, or 
        // false on error.      Connect to the server with the provided 
        // arguments. The connection to the server will be closed 
        // when the script terminates, unless close() function is 
        // called beforehand
        function connect($argHostname = "", $argUsername = "", 
                $argPassword = "", $argDatabaseName = "") 
        {
                $connString = "";
                $hostPieces = array();
                /*      Must specify the database argument      */
                if (!$argDatabaseName) {        
                        return false;
                }
                if ($argHostname != "") {
                        $this->hostname = $argHostname;
                }
                if ($argUsername != "") {
                        $this->username = $argUsername;
                }
                if ($argPassword != "") {
                        $this->password = $argPassword;
                }
                if ($argDatabaseName != "") {
                        $this->databaseName = $argDatabaseName;
                }                               
                $hostPieces = split(":", $this->hostname);
                if ($hostPieces[0]) {
                        $connString .= "host=$hostPieces[0]";
                        if (isset($hostPieces[1])) {
                                $connString .= " port=$hostPieces[1]";
                        }                       
                }
            if ($this->username) {
                        $connString .= " user=$this->username";
                }
            if ($this->password) {
                        $connString .= " password=$this->password";
                }
                $connString .= " dbname=$this->databaseName";
                        
                $this->_connectionID = @pg_Connect($connString);
                return $this->_connectionID;
        }

        // Returns: A positive link identifier on success, or
        // false on error.  Connect to the server with the 
        // provided arguments. The connection to the server will 
        // not be closed when the script terminates. Instead it 
        // will be kept for later future use
        function pconnect($argHostname = "", $argUsername = "", 
                $argPassword = "", $argDatabaseName = "") 
        {
                $connString = "";
                $hostPieces = array();          
                /*      Must specify the database argument      */
                if (!$argDatabaseName) {
                        return false;
                }
                if ($argHostname != "") {
                        $this->hostname = $argHostname;
                }
                if ($argUsername != "") {
                        $this->username = $argUsername;
                }
                if ($argPassword != "") {
                        $this->password = $argPassword;
                }
                if ($argDatabaseName != "") {
                        $this->databaseName = $argDatabaseName;
                }                               
                $hostPieces = split(":", $this->hostname);
                if ($hostPieces[0]) {
                        $connString .= "host=$hostPieces[0]";
                        if (isset($hostPieces[1])) {
                                $connString .= " port=$hostPieces[1]";
                        }                       
                }
            if ($this->username) {
                        $connString .= " user=$this->username";
                }
            if ($this->password) {
                        $connString .= " password=$this->password";
                }
                $connString .= " dbname=$this->databaseName";
                        
                $this->_connectionID = @pg_pConnect($connString);
                if ($this->_connectionID) {
                        $this->_isPersistentConnection = true;                          
                }
                return $this->_connectionID;
        }               
        
        // Returns: true on success, false on error Select 
        // the database name to be used PostgreSQL 
        // Note:        function Not available
        function selectDB($dbName) {
                        return false;
        }

        // Returns: the Recordset object disregard success 
        // or failure Send the sql statement to the database server
        function execute($sql = "") {
                // Instantiate an object without considering whether 
                // the query return any results or not
                $this->_queryID = @pg_Exec($this->_connectionID, $sql);
                $this->_tempResultObj = new Recordset($this->_queryID);
                $this->_insertQuery($this->_queryID);
                return $this->_tempResultObj;
        }
        
        // Returns: the last error message from previous 
        // database operation
        function errorMsg() {
                $this->_errorMsg = @pg_errormessage($this->_connectionID);
            return $this->_errorMsg;
        }

        // Returns: true on success, false on failure 
        // Close the database connection
        function close() {
                if ($this->_queryIDList && sizeof($this->_queryIDList > 0)) {
                        while(list($_key, $_resultID) = each($this->_queryIDList)) {
                                @pg_freeresult($_resultID);
                        }
                }
                // If its not a persistent connection, then 
                // only the connection needs to be closed
                if ($this->_isPersistentConnection != true) {   
                        return @pg_close($this->_connectionID);
                }
                else {
                        return true;
                }
        }
        
        // A PRIVATE function used by the constructor function 
        // of the query object.  insert the successful returned
        // query id to the query id list.  Used for later results 
        // cleanup.  A private function that's never meant to 
        // be used directly
        function _insertQuery($query_id) {
                $this->_queryIDList[] = $query_id;
        }               
}
        
//------------------------------
         Class Name: Recordset
//------------------------------
class Recordset 
{
        /*      public variables        */
        var $fields;
        // indicates that the current record position is before 
        // the first record in a Recordset object
        var $BOF = null;

        // indicates that the current record position is after
        // the last record in a Recordset object
        var $EOF = null;        
        
        /*      private variables       */
        var $_numOfRows = -1; // NEVER change the value! READ-ONLY!
        var $_numOfFields = -1; // NEVER change the value! READ-ONLY!
        // Holds anything that was returned from the database specific functions
        var $_tempResult = ''; 
        // This variable keeps the result link identifier
        var $_queryID = -1;     
        // This variable keeps the current row in the Recordset
        var $_currentRow = -1;

        // Returns: query id on success and false if 
        // failed Constructor function
        function Recordset($queryID) 
        {
                $this->_queryID = $queryID;
                if ($queryID) {
                        $this->_numOfRows = @pg_numrows($this->_queryID);
                        /*      pg_numrows() returns -1 on error        */
                        if ($this->_numOfRows == -1) {
                                $this->_numOfRows = 0;
                        }
                        $this->_numOfFields = @pg_numfields($this->_queryID);
                        /*      pg_numfields() returns -1 on error      */
                        if ($this->_numOfFields == -1) {
                                $this->_numOfFields = 0;
                        }
                }
                else {
                        $this->_numOfRows = 0;
                        $this->_numOfFields = 0;
                }
                /*      If result set contains rows     */
                if ($this->_numOfRows > 0 && $this->_currentRow == -1) {
                        $this->_currentRow = 0;
                        $this->fields = @pg_fetch_array($this->_queryID, $this->_currentRow);                   
                        $this->EOF = false;
                        $this->BOF = false;
                }
                return $this->_queryID;
        }
                
        // Returns: true if successful, false if fail Set the Recordset 
        // pointer to a specified field offset. If the next call to 
        // fetchField() won't include a field offset, this field would 
        // be returned.  PostgreSQL Note:       function Not available
        function fieldSeek($fieldOffset = -1) {
                $this->_tempResult = false;
                return $this->_tempResult;
        }

        // Returns: an object containing field information.  Get column 
        // information in the Recordset object. fetchField() can be used 
        // in order to obtain information about fields in a certain query 
        // result. If the field offset isn't specified, the next field 
        // that wasn't yet retrieved by fetchField() is retrieved. 
        // PostgreSQL Note:     function Not available
        function fetchField($fieldOffset = -1) {
                $this->_tempResult = false;             
                return $this->_tempResult;
        }                               

        // Returns: true if there still rows available, or false if there 
        // are no more rows.  Moves to the next row in a specified Recordset 
        // object and makes that record the current row and the data 
        // corresponding to the row will be retrieved into the fields 
        // collection.  Note: Unlike the moveRow() method, when _currentRow
        // is getNumOfRows() - 1, EOF will immediately be true.  If row number
        // is not provided, the function will point to the 
        // first row automatically
        function nextRow() {
                if ($this->getNumOfRows() > 0) {                        
                        $this->fields = array();
                        $this->_currentRow++;
                        $this->fields = @pg_fetch_array($this->_queryID, $this->_currentRow);
                        /*      This is not working.  True all the time */
                        if ($this->fields) {
                                $this->_checkAndChangeEOF($this->_currentRow - 1);
                                return true;
                        }
                }
                $this->EOF = true;
                return false;
        }       
                        
        // Returns: true on success, false on failure moveRow() moves 
        // the internal row pointer of the Recordset object to point 
        // to the specified row number and the data corresponding to
        // the row will be retrieved into the fields collection.  If 
        // row number is not provided, the function will point to 
        // the first row automatically
        function moveRow($rowNumber = 0) {
                if ($rowNumber == 0) {
                        return $this->firstRow();
                }
                else if ($rowNumber == ($this->getNumOfRows() - 1)) {
                        return $this->lastRow();
                }
                if ($this->getNumOfRows() > 0 && $rowNumber < $this->getNumOfRows()) {       
                        $this->fields = null;
                        $this->_currentRow = $rowNumber;
                        $this->fields = @pg_fetch_array($this->_queryID, $this->_currentRow);
                        /*      This is not working.  True all the time */
                        if ($this->fields) {
                                // No need to call _checkAndChangeEOF() because 
                                // the possibility of moving to the last row 
                                // has been handled by the above code
                                $this->EOF = false;
                                return true;
                        }
                }
                $this->EOF = true;
                return false;
        }

        // Returns: true on success, false on failure firstRow() 
        // moves the internal row pointer of the Recordset object
        // to the first row and the data corresponding to the row 
        // will be retrieved into the fields collection
        function firstRow() {
                if ($this->getNumOfRows() > 0) {
                        $this->fields = array();
                        $this->_currentRow = 0;
                        $this->fields = @pg_fetch_array($this->_queryID, $this->_currentRow);
                        $this->EOF = true;
                        /*      This is not working.  True all the time */
                        if ($this->fields) {
                                return true;    
                        }
                }
                $this->EOF = true;
                return false;           
        }

        // Returns: true on success, false on failure lastRow() 
        // moves the internal row pointer of the Recordset object 
        // to the last row and the data corresponding to the row 
        // will be retrieved into the fields collection
        function lastRow() {
                if ($this->getNumOfRows() > 0) {        
                        $this->fields = array();        
                        $num_of_rows = $this->getNumOfRows();
                        /*      $num_of_rows decemented at above        */
                        $this->_currentRow = --$num_of_rows;    
                        $this->fields = @pg_fetch_array($this->_queryID, $this->_currentRow);
                        /*      This is not working.  True all the time */
                        if ($this->fields) {
                                /*      Special case for making EOF false.      */
                                $this->EOF = false;     
                                return true;
                        }
                }
                $this->EOF = true;
                return false;
        }

        // close() only needs to be called if you are worried about 
        // using too much memory while your script is running. All 
        // associated result memory for the specified result identifier 
        // will automatically be freed
        function close() {
                $this->_tempResult = @pg_freeresult($this->_queryID);           
                return $this->_tempResult;
        }

        // Returns: the number of rows in a result set.  
        // Get number of rows in result
        function getNumOfRows() {
                return $this->_numOfRows;
        }

        // Returns: the number of fields in a result set.
        // Get number of fields in result
        function getNumOfFields() {
                return $this->_numOfFields;
        }       

        /*      Check and change the status of EOF.     */              
        function _checkAndChangeEOF($currentRow) {
                if ($currentRow >= ($this->_numOfRows - 1)) {
                        $this->EOF = true;
                }               
                else {
                        $this->EOF = false;             
                }
        }
}
?>


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