includes/libs/rdbms/database/resultwrapper/IResultWrapper.php

   1 <?php
   2
   3 namespace Wikimedia\Rdbms;
   4
   5 use Iterator;
   6 use DBUnexpectedError;
   7 use stdClass;
   8
   9 /**
  10  * Result wrapper for grabbing data queried from an IDatabase object
  11  *
  12  * Note that using the Iterator methods in combination with the non-Iterator
  13  * DB result iteration functions may cause rows to be skipped or repeated.
  14  *
  15  * By default, this will use the iteration methods of the IDatabase handle if provided.
  16  * Subclasses can override methods to make it solely work on the result resource instead.
  17  * If no database is provided, and the subclass does not override the DB iteration methods,
  18  * then a RuntimeException will be thrown when iteration is attempted.
  19  *
  20  * The result resource field should not be accessed from non-Database related classes.
  21  * It is database class specific and is stored here to associate iterators with queries.
  22  *
  23  * @ingroup Database
  24  */
  25 interface IResultWrapper extends Iterator {
  26         /**
  27          * Get the number of rows in a result object
  28          *
  29          * @return int
  30          */
  31         public function numRows();
  32
  33         /**
  34          * Fetch the next row from the given result object, in object form. Fields can be retrieved with
  35          * $row->fieldname, with fields acting like member variables. If no more rows are available,
  36          * false is returned.
  37          *
  38          * @return stdClass|bool
  39          * @throws DBUnexpectedError Thrown if the database returns an error
  40          */
  41         public function fetchObject();
  42
  43         /**
  44          * Fetch the next row from the given result object, in associative array form. Fields are
  45          * retrieved with $row['fieldname']. If no more rows are available, false is returned.
  46          *
  47          * @return array|bool
  48          * @throws DBUnexpectedError Thrown if the database returns an error
  49          */
  50         public function fetchRow();
  51
  52         /**
  53          * Change the position of the cursor in a result object.
  54          * See mysql_data_seek()
  55          *
  56          * @param int $row
  57          */
  58         public function seek( $row );
  59
  60         /**
  61          * Free a result object
  62          *
  63          * This either saves memory in PHP (buffered queries) or on the server (unbuffered queries).
  64          * In general, queries are not large enough in result sets for this to be worth calling.
  65          */
  66         public function free();
  67
  68         /**
  69          * @return stdClass|array|bool
  70          */
  71         public function current();
  72
  73         /**
  74          * @return int
  75          */
  76         public function key();
  77
  78         /**
  79          * @return stdClass
  80          */
  81         function next();
  82 }