[Sommaire] [Imprimer]

   1  <?php
   2  /*
   3   *  $Id: MSSQLResultSet.php,v 1.21 2006/01/17 19:44:38 hlellelid Exp $
   4   *
   5   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   6   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   7   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   8   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   9   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  10   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  11   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  12   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  13   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  14   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  15   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  16   *
  17   * This software consists of voluntary contributions made by many individuals
  18   * and is licensed under the LGPL. For more information please see
  19   * <http://creole.phpdb.org>.
  20   */
  21  
  22  require_once 'creole/ResultSet.php';
  23  require_once 'creole/common/ResultSetCommon.php';
  24  
  25  /**
  26   * MSSQL implementation of ResultSet.
  27   *
  28   * MS SQL does not support LIMIT or OFFSET natively so the methods
  29   * in here need to perform some adjustments and extra checking to make sure
  30   * that this behaves the same as RDBMS drivers using native OFFSET/LIMIT.
  31   * 
  32   * @author    Hans Lellelid <hans@xmpl.org>
  33   * @version   $Revision: 1.21 $
  34   * @package   creole.drivers.mssql
  35   */
  36  class MSSQLResultSet extends ResultSetCommon implements ResultSet {    
  37      
  38      /**
  39       * Offset at which to start reading rows.
  40       * @var int
  41       */
  42      private $offset = 0;
  43      
  44      /**
  45       * Maximum rows to retrieve, or 0 if all.
  46       * @var int
  47       */
  48      private $limit = 0;   
  49      
  50      /**
  51       * This MSSQL-only function exists to set offset after ResultSet is instantiated.
  52       * This function should be "protected" in Java sense: only available to classes in package.
  53       * THIS METHOD SHOULD NOT BE CALLED BY ANYTHING EXCEPTION DRIVER CLASSES.
  54       * @param int $offset New offset.  If great than 0, then seek(0) will be called to move cursor.
  55       * @access protected
  56       */
  57      public function _setOffset($offset)
  58      {
  59          $this->offset = $offset;
  60          if ($offset > 0) {
  61              $this->seek(0);  // 0 becomes $offset by seek() method
  62          }
  63      }
  64      
  65      /**
  66       * This MSSQL-only function exists to set limit after ResultSet is instantiated.
  67       * This function should be "protected" in Java sense: only available to classes in package.
  68       * THIS METHOD SHOULD NOT BE CALLED BY ANYTHING EXCEPTION DRIVER CLASSES.
  69       * @param int $limit New limit.
  70       * @access protected
  71       */
  72      public function _setLimit($limit)
  73      {
  74          $this->limit = $limit;
  75      }
  76      
  77      /**
  78       * @see ResultSet::seek()
  79       */ 
  80      function seek($rownum)
  81      {
  82          // support emulated OFFSET
  83          $actual = $rownum + $this->offset;
  84          
  85          if (($this->limit > 0 && $rownum >= $this->limit) || $rownum < 0) {
  86                      // have to check for rownum < 0, because mssql_seek() won't
  87                      // complain if the $actual is valid.
  88              return false;
  89          }
  90                  
  91          // MSSQL rows start w/ 0, but this works, because we are
  92          // looking to move the position _before_ the next desired position
  93           if (!@mssql_data_seek($this->result, $actual)) {
  94                  return false;
  95          }
  96  
  97          $this->cursorPos = $rownum;
  98          return true;
  99      }
 100      
 101      /**
 102       * @see ResultSet::next()
 103       */
 104      function next()
 105      {
 106          // support emulated LIMIT
 107          if ( $this->limit > 0 && ($this->cursorPos >= $this->limit) ) {
 108              $this->afterLast();
 109              return false;
 110          }
 111          
 112          $this->fields = mssql_fetch_array($this->result, $this->fetchmode);        
 113                  
 114          if (!$this->fields) {
 115              if ($errmsg = mssql_get_last_message()) {
 116                  throw new SQLException("Error fetching result", $errmsg);
 117               } else {
 118                  // We've advanced beyond end of recordset.
 119                  $this->afterLast();
 120                  return false;
 121               }          
 122          }
 123          
 124          if ($this->fetchmode === ResultSet::FETCHMODE_ASSOC && $this->lowerAssocCase) {
 125              $this->fields = array_change_key_case($this->fields, CASE_LOWER);
 126          }
 127          
 128          // Advance cursor position
 129          $this->cursorPos++;
 130          return true;
 131      }
 132      
 133      /**
 134       * @see ResultSet::getRecordCount()
 135       */
 136      function getRecordCount()
 137      {
 138          $rows = @mssql_num_rows($this->result);
 139          if ($rows === null) {
 140              throw new SQLException('Error getting record count', mssql_get_last_message());
 141          }
 142          // adjust count based on emulated LIMIT/OFFSET
 143          $rows -= $this->offset;
 144          return ($this->limit > 0 && $rows > $this->limit ? $this->limit : $rows);
 145      }
 146  
 147      /**
 148       * @see ResultSet::close()
 149       */ 
 150      function close()
 151      {
 152          $ret = @mssql_free_result($this->result);
 153          $this->result = false;
 154          $this->fields = array();
 155          $this->limit = 0;
 156          $this->offset = 0;        
 157      }   
 158  
 159  }