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

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