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   1  <?php
   2  //  backPress DB Class
   3  
   4  //  ORIGINAL CODE FROM:
   5  //  Justin Vincent (justin@visunet.ie)
   6  //    http://php.justinvincent.com
   7  
   8  define( 'EZSQL_VERSION', 'BP1.25' );
   9  define( 'OBJECT', 'OBJECT', true );
  10  define( 'OBJECT_K', 'OBJECT_K', false );
  11  define( 'ARRAY_A', 'ARRAY_A', false );
  12  define( 'ARRAY_K', 'ARRAY_K', false );
  13  define( 'ARRAY_N', 'ARRAY_N', false );
  14  
  15  if ( !defined( 'SAVEQUERIES' ) ) {
  16      define( 'SAVEQUERIES', false );
  17  }
  18  
  19  if ( !defined( 'BPDB__ERROR_STRING' ) ) {
  20      define( 'BPDB__ERROR_STRING', 'DB Error: %s, %s: %s' );
  21  }
  22  if ( !defined( 'BPDB__ERROR_HTML' ) ) {
  23      define( 'BPDB__ERROR_HTML', '<div class="error"><p><strong>DB Error in %3$s:</strong> %1$s</p><pre>%2$s</pre></div>' );
  24  }
  25  if ( !defined( 'BPDB__CONNECT_ERROR_MESSAGE' ) ) {
  26      define( 'BPDB__CONNECT_ERROR_MESSAGE', 'DB Error: cannot connect' );
  27  }
  28  if ( !defined( 'BPDB__SELECT_ERROR_MESSAGE' ) ) {
  29      define( 'BPDB__SELECT_ERROR_MESSAGE', 'DB Error: cannot select' );
  30  }
  31  if ( !defined( 'BPDB__DB_VERSION_ERROR' ) ) {
  32      define( 'BPDB__DB_VERSION_ERROR', 'DB Requires MySQL version 4.0 or higher' );
  33  }
  34  if ( !defined( 'BPDB__PHP_EXTENSION_MISSING' ) ) {
  35      define( 'BPDB__PHP_EXTENSION_MISSING', 'DB Requires The MySQL PHP extension' );
  36  }
  37  
  38  class BPDB
  39  {
  40      /**
  41       * Whether to show SQL/DB errors
  42       *
  43       * @since 1.0
  44       * @access private
  45       * @var bool
  46       */
  47      var $show_errors = false;
  48  
  49      /**
  50       * Whether to suppress errors during the DB bootstrapping.
  51       *
  52       * @access private
  53       * @since 1.0
  54       * @var bool
  55       */
  56      var $suppress_errors = false;
  57  
  58      /**
  59       * The last error during query.
  60       *
  61       * @since 1.0
  62       * @var string
  63       */
  64      var $last_error = '';
  65  
  66      /**
  67       * Amount of queries made
  68       *
  69       * @since 1.0
  70       * @access private
  71       * @var int
  72       */
  73      var $num_queries = 0;
  74  
  75      /**
  76       * The last query made
  77       *
  78       * @since 1.0
  79       * @access private
  80       * @var string
  81       */
  82      var $last_query = null;
  83  
  84      /**
  85       * Saved info on the table column
  86       *
  87       * @since 1.0
  88       * @access private
  89       * @var array
  90       */
  91      var $col_info = array();
  92      
  93      /**
  94       * Saved queries that were executed
  95       *
  96       * @since 1.0
  97       * @access private
  98       * @var array
  99       */
 100      var $queries = array();
 101  
 102      /**
 103       * Whether to use the query log
 104       *
 105       * @since 1.0
 106       * @access private
 107       * @var bool
 108       */
 109      var $save_queries = false;
 110  
 111      /**
 112       * Table prefix
 113       *
 114       * You can set this to have multiple installations
 115       * in a single database. The second reason is for possible
 116       * security precautions.
 117       *
 118       * @since 1.0
 119       * @access private
 120       * @var string
 121       */
 122      var $prefix = '';
 123      
 124      /**
 125       * Whether the database queries are ready to start executing.
 126       *
 127       * @since 1.0
 128       * @access private
 129       * @var bool
 130       */
 131      var $ready = false;
 132  
 133      /**
 134       * The currently connected MySQL connection resource.
 135       *
 136       * @since 1.0
 137       * @access private
 138       * @var bool|resource
 139       */
 140      var $dbh = false;
 141  
 142      /**
 143       * List of tables
 144       *
 145       * @since 1.0
 146       * @access private
 147       * @var array
 148       */
 149      var $tables = array();
 150  
 151      /**
 152       * Whether to use mysql_real_escape_string
 153       *
 154       * @since 1.0
 155       * @access public
 156       * @var bool
 157       */
 158      var $real_escape = false;
 159  
 160      /**
 161       * PHP4 style constructor
 162       *
 163       * @since 1.0
 164       *
 165       * @return unknown Returns the result of bpdb::__construct()
 166       */
 167  	function BPDB()
 168      {
 169          $args = func_get_args();
 170          register_shutdown_function( array( &$this, '__destruct' ) );
 171          return call_user_func_array( array( &$this, '__construct' ), $args );
 172      }
 173  
 174      /**
 175       * PHP5 style constructor
 176       *
 177       * Grabs the arguments, calls bpdb::_init() and then connects to the database
 178       *
 179       * @since 1.0
 180       *
 181       * @return void
 182       */
 183  	function __construct()
 184      {
 185          $args = func_get_args();
 186          $args = call_user_func_array( array( &$this, '_init' ), $args );
 187  
 188          $this->db_connect_host( $args );
 189      }
 190  
 191      /**
 192       * Initialises the class variables based on provided arguments
 193       *
 194       * @since 1.0
 195       *
 196       * @param array $args The provided connection settings
 197       * @return array The current connection settings after processing by init
 198       */
 199  	function _init( $args )
 200      {
 201          if ( !extension_loaded( 'mysql' ) ) {
 202              $this->show_errors();
 203              $this->bail( BPDB__PHP_EXTENSION_MISSING );
 204              return;
 205          }
 206  
 207          if ( 4 == func_num_args() ) {
 208              $args = array(
 209                  'user' => $args,
 210                  'password' => func_get_arg( 1 ),
 211                  'name' => func_get_arg( 2 ),
 212                  'host' => func_get_arg( 3 )
 213              );
 214          }
 215  
 216          $defaults = array(
 217              'user' => false,
 218              'password' => false,
 219              'name' => false,
 220              'host' => 'localhost',
 221              'charset' => false,
 222              'collate' => false,
 223              'errors' => false
 224          );
 225  
 226          $args = wp_parse_args( $args, $defaults );
 227  
 228          switch ( $args['errors'] ) {
 229              case 'show' :
 230                  $this->show_errors( true );
 231                  break;
 232              case 'suppress' :
 233                  $this->suppress_errors( true );
 234                  break;
 235          }
 236  
 237          return $args;
 238      }
 239  
 240      /**
 241       * PHP5 style destructor, registered as shutdown function in PHP4
 242       *
 243       * @since 1.0
 244       *
 245       * @return bool Always returns true
 246       */
 247  	function __destruct()
 248      {
 249          return true;
 250      }
 251  
 252      /**
 253       * Figure out which database server should handle the query, and connect to it.
 254       *
 255       * @since 1.0
 256       *
 257       * @param string query
 258       * @return resource mysql database connection
 259       */
 260      function &db_connect( $query = '' )
 261      {
 262          $false = false;
 263          if ( empty( $query ) ) {
 264              return $false;
 265          }
 266          return $this->dbh;
 267      }
 268  
 269      /**
 270       * Connects to the database server and selects a database
 271       *
 272       * @since 1.0
 273       *
 274       * @param array args
 275       *    name => string DB name (required)
 276       *    user => string DB user (optional: false)
 277       *    password => string DB user password (optional: false)
 278       *    host => string DB hostname (optional: 'localhost')
 279       *    charset => string DB default charset.  Used in a SET NAMES query. (optional)
 280       *    collate => string DB default collation.  If charset supplied, optionally added to the SET NAMES query (optional)
 281       * @return void|bool void if cannot connect, false if cannot select, true if success
 282       */
 283  	function db_connect_host( $args )
 284      {
 285          extract( $args, EXTR_SKIP );
 286  
 287          unset( $this->dbh ); // De-reference before re-assigning
 288          $this->dbh = @mysql_connect( $host, $user, $password, true );
 289  
 290          if ( !$this->dbh ) {
 291              if ( !$this->suppress_errors ) {
 292                  $this->show_errors();
 293              }
 294              $this->bail( BPDB__CONNECT_ERROR_MESSAGE );
 295              return;
 296          }
 297  
 298          $this->ready = true;
 299  
 300          if ( $this->has_cap( 'collation' ) ) {
 301              if ( !empty( $charset ) ) {
 302                  if ( function_exists( 'mysql_set_charset' ) ) {
 303                      mysql_set_charset( $charset, $this->dbh );
 304                      $this->real_escape = true;
 305                  } else {
 306                      $collation_query = "SET NAMES '{$charset}'";
 307                      if ( !empty( $collate ) ) {
 308                          $collation_query .= " COLLATE '{$collate}'";
 309                      }
 310                      $this->query( $collation_query, true );
 311                  }
 312              }
 313          }
 314  
 315          return $this->select( $name, $this->dbh );
 316      }
 317  
 318      /**
 319       * Sets the table prefix for the WordPress tables.
 320       *
 321       * @since 1.0
 322       *
 323       * @param string prefix
 324       * @param false|array tables (optional: false)
 325       *    table identifiers are array keys
 326       *    array values
 327       *        empty: set prefix: array( 'posts' => false, 'users' => false, ... )
 328       *        string: set to that array value: array( 'posts' => 'my_posts', 'users' => 'my_users' )
 329       *    OR array values (with numeric keys): array( 'posts', 'users', ... )
 330       *
 331       * @return string the previous prefix (mostly only meaningful if all $table parameter was false)
 332       */
 333  	function set_prefix( $prefix, $tables = false )
 334      {
 335          if ( !$prefix ) {
 336              return false;
 337          }
 338          if ( preg_match( '|[^a-z0-9_]|i', $prefix ) ) {
 339              return new WP_Error( 'invalid_db_prefix', 'Invalid database prefix' ); // No gettext here
 340          }
 341  
 342          $old_prefix = $this->prefix;
 343  
 344          if ( $tables && is_array( $tables ) ) {
 345              $_tables =& $tables;
 346          } else {
 347              $_tables =& $this->tables;
 348              $this->prefix = $prefix;
 349          }
 350  
 351          foreach ( $_tables as $key => $value ) {
 352              if ( is_numeric( $key ) ) { // array( 'posts', 'users', ... )
 353                  $this->$value = $prefix . $value;
 354              } elseif ( !$value ) {
 355                  $this->$key = $prefix . $key; // array( 'posts' => false, 'users' => false, ... )
 356              } elseif ( is_string( $value ) ) { // array( 'posts' => 'my_posts', 'users' => 'my_users' )
 357                  $this->$key = $value;
 358              }
 359          }
 360  
 361          return $old_prefix;
 362      }
 363  
 364      /**
 365       * Selects a database using the current database connection.
 366       *
 367       * The database name will be changed based on the current database
 368       * connection. On failure, the execution will bail and display an DB error.
 369       *
 370       * @since 1.0
 371       *
 372       * @param string $db MySQL database name
 373       * @return bool True on success, false on failure.
 374       */
 375  	function select( $db, &$dbh )
 376      {
 377          if ( !@mysql_select_db( $db, $dbh ) ) {
 378              $this->ready = false;
 379              $this->show_errors();
 380              $this->bail( BPDB__SELECT_ERROR_MESSAGE );
 381              return false;
 382          }
 383          return true;
 384      }
 385  
 386  	function _weak_escape( $string )
 387      {
 388          return addslashes( $string );
 389      }
 390  
 391  	function _real_escape( $string )
 392      {
 393          if ( $this->dbh && $this->real_escape ) {
 394              return mysql_real_escape_string( $string, $this->dbh );
 395          } else {
 396              return addslashes( $string );
 397          }
 398      }
 399  
 400  	function _escape( $data )
 401      {
 402          if ( is_array( $data ) ) {
 403              foreach ( (array) $data as $k => $v ) {
 404                  if ( is_array( $v ) ) {
 405                      $data[$k] = $this->_escape( $v );
 406                  } else {
 407                      $data[$k] = $this->_real_escape( $v );
 408                  }
 409              }
 410          } else {
 411              $data = $this->_real_escape( $data );
 412          }
 413  
 414          return $data;
 415      }
 416  
 417      /**
 418       * Escapes content for insertion into the database using addslashes(), for security
 419       *
 420       * @since 1.0
 421       *
 422       * @param string|array $data
 423       * @return string query safe string
 424       */
 425  	function escape( $data )
 426      {
 427          if ( is_array( $data ) ) {
 428              foreach ( (array) $data as $k => $v ) {
 429                  if ( is_array( $v ) ) {
 430                      $data[$k] = $this->escape( $v );
 431                  } else {
 432                      $data[$k] = $this->_weak_escape( $v );
 433                  }
 434              }
 435          } else {
 436              $data = $this->_weak_escape( $data );
 437          }
 438  
 439          return $data;
 440      }
 441  
 442      /**
 443       * Escapes content by reference for insertion into the database, for security
 444       *
 445       * @since 1.0
 446       *
 447       * @param string $s
 448       */
 449  	function escape_by_ref( &$string )
 450      {
 451          $string = $this->_real_escape( $string );
 452      }
 453  
 454      /**
 455       * Escapes array recursively for insertion into the database, for security
 456       * @param array $array
 457       */
 458  	function escape_deep( $array )
 459      {
 460          return $this->_escape( $array );
 461      }
 462  
 463      /**
 464       * Prepares a SQL query for safe execution.  Uses sprintf()-like syntax.
 465       *
 466       * This function only supports a small subset of the sprintf syntax; it only supports %d (decimal number), %s (string).
 467       * Does not support sign, padding, alignment, width or precision specifiers.
 468       * Does not support argument numbering/swapping.
 469       *
 470       * May be called like {@link http://php.net/sprintf sprintf()} or like {@link http://php.net/vsprintf vsprintf()}.
 471       *
 472       * Both %d and %s should be left unquoted in the query string.
 473       *
 474       * <code>
 475       * wpdb::prepare( "SELECT * FROM `table` WHERE `column` = %s AND `field` = %d", "foo", 1337 )
 476       * </code>
 477       *
 478       * @link http://php.net/sprintf Description of syntax.
 479       * @since 1.0
 480       *
 481       * @param string $query Query statement with sprintf()-like placeholders
 482       * @param array|mixed $args The array of variables to substitute into the query's placeholders if being called like {@link http://php.net/vsprintf vsprintf()}, or the first variable to substitute into the query's placeholders if being called like {@link http://php.net/sprintf sprintf()}.
 483       * @param mixed $args,... further variables to substitute into the query's placeholders if being called like {@link http://php.net/sprintf sprintf()}.
 484       * @return null|string Sanitized query string
 485       */
 486  	function prepare( $query = null ) // ( $query, *$args )
 487      {
 488          if ( is_null( $query ) ) {
 489              return;
 490          }
 491          $args = func_get_args();
 492          array_shift( $args );
 493          // If args were passed as an array (as in vsprintf), move them up
 494          if ( isset( $args[0] ) && is_array( $args[0] ) ) {
 495              $args = $args[0];
 496          }
 497          $query = str_replace( "'%s'", '%s', $query ); // in case someone mistakenly already singlequoted it
 498          $query = str_replace( '"%s"', '%s', $query ); // doublequote unquoting
 499          $query = str_replace( '%s', "'%s'", $query ); // quote the strings
 500          array_walk( $args, array( &$this, 'escape_by_ref' ) );
 501          return @vsprintf( $query, $args );
 502      }
 503  
 504      /**
 505       * Get SQL/DB error
 506       *
 507       * @since 1.0
 508       *
 509       * @param string $str Error string
 510       */
 511  	function get_error( $str = '' )
 512      {
 513          if ( empty( $str ) ) {
 514              if ( $this->last_error ) {
 515                  $str = $this->last_error;
 516              } else {
 517                  return false;
 518              }
 519          }
 520  
 521          $caller = $this->get_caller();
 522          $error_str = sprintf( BPDB__ERROR_STRING, $str, $this->last_query, $caller );
 523  
 524          if ( class_exists( 'WP_Error' ) ) {
 525              return new WP_Error( 'db_query', $error_str, array( 'query' => $this->last_query, 'error' => $str, 'caller' => $caller ) );
 526          } else {
 527              return array( 'query' => $this->last_query, 'error' => $str, 'caller' => $caller, 'error_str' => $error_str );
 528          }
 529      }
 530  
 531      /**
 532       * Print SQL/DB error.
 533       *
 534       * @since 1.0
 535       *
 536       * @param string $str The error to display
 537       * @return bool False if the showing of errors is disabled.
 538       */
 539  	function print_error( $str = '' )
 540      {
 541          if ( $this->suppress_errors ) {
 542              return false;
 543          }
 544  
 545          $error = $this->get_error( $str );
 546          if ( is_object( $error ) && is_a( $error, 'WP_Error' ) ) {
 547              $err = $error->get_error_data();
 548              $err['error_str'] = $error->get_error_message();
 549          } else {
 550              $err =& $error;
 551          }
 552  
 553          $log_file = ini_get( 'error_log' );
 554          if ( !empty( $log_file ) && ( 'syslog' != $log_file ) && is_writable( $log_file ) && function_exists( 'error_log' ) ) {
 555              error_log($err['error_str'], 0);
 556          }
 557  
 558          // Is error output turned on or not
 559          if ( !$this->show_errors ) {
 560              return false;
 561          }
 562  
 563          $str = htmlspecialchars( $err['error'], ENT_QUOTES );
 564          $query = htmlspecialchars( $err['query'], ENT_QUOTES );
 565          $caller = htmlspecialchars( $err['caller'], ENT_QUOTES );
 566  
 567          // If there is an error then take note of it
 568  
 569          printf( BPDB__ERROR_HTML, $str, $query, $caller );
 570      }
 571  
 572      /**
 573       * Enables showing of database errors.
 574       *
 575       * This function should be used only to enable showing of errors.
 576       * bpdb::hide_errors() should be used instead for hiding of errors. However,
 577       * this function can be used to enable and disable showing of database
 578       * errors.
 579       *
 580       * @since 1.0
 581       *
 582       * @param bool $show Whether to show or hide errors
 583       * @return bool Old value for showing errors.
 584       */
 585  	function show_errors( $show = true )
 586      {
 587          $errors = $this->show_errors;
 588          $this->show_errors = $show;
 589          return $errors;
 590      }
 591  
 592      /**
 593       * Disables showing of database errors.
 594       *
 595       * @since 1.0
 596       *
 597       * @return bool Whether showing of errors was active or not
 598       */
 599  	function hide_errors()
 600      {
 601          return $this->show_errors( false );
 602      }
 603  
 604      /**
 605       * Whether to suppress database errors.
 606       *
 607       * @since 1.0
 608       *
 609       * @param bool $suppress
 610       * @return bool previous setting
 611       */
 612  	function suppress_errors( $suppress = true )
 613      {
 614          $errors = $this->suppress_errors;
 615          $this->suppress_errors = $suppress;
 616          return $errors;
 617      }
 618  
 619      /**
 620       * Kill cached query results.
 621       *
 622       * @since 1.0
 623       */
 624  	function flush()
 625      {
 626          $this->last_result = array();
 627          $this->col_info = array();
 628          $this->last_query = null;
 629          $this->last_error = '';
 630          $this->num_rows = 0;
 631      }
 632  
 633      /**
 634       * Perform a MySQL database query, using current database connection.
 635       *
 636       * More information can be found on the codex page.
 637       *
 638       * @since 1.0
 639       *
 640       * @param string $query
 641       * @return int|false Number of rows affected/selected or false on error
 642       */
 643  	function query( $query, $use_current = false )
 644      {
 645          if ( !$this->ready ) {
 646              return false;
 647          }
 648  
 649          // filter the query, if filters are available
 650          // NOTE: some queries are made before the plugins have been loaded, and thus cannot be filtered with this method
 651          if ( function_exists( 'apply_filters' ) ) {
 652              $query = apply_filters( 'query', $query );
 653          }
 654  
 655          // initialise return
 656          $return_val = 0;
 657          $this->flush();
 658  
 659          // Log how the function was called
 660          $this->func_call = "\$db->query(\"$query\")";
 661  
 662          // Keep track of the last query for debug..
 663          $this->last_query = $query;
 664  
 665          // Perform the query via std mysql_query function..
 666          if ( SAVEQUERIES ) {
 667              $this->timer_start();
 668          }
 669  
 670          if ( $use_current ) {
 671              $dbh =& $this->dbh;
 672          } else {
 673              $dbh = $this->db_connect( $query );
 674          }
 675  
 676          $this->result = @mysql_query( $query, $dbh );
 677          ++$this->num_queries;
 678  
 679          if ( SAVEQUERIES ) {
 680              $this->queries[] = array( $query, $this->timer_stop(), $this->get_caller() );
 681          }
 682  
 683          // If there is an error then take note of it..
 684          if ( $this->last_error = mysql_error( $dbh ) ) {
 685              return $this->print_error( $this->last_error );
 686          }
 687  
 688          if ( preg_match( "/^\\s*(insert|delete|update|replace|alter) /i", $query ) ) {
 689              $this->rows_affected = mysql_affected_rows( $dbh );
 690              // Take note of the insert_id
 691              if ( preg_match( "/^\\s*(insert|replace) /i", $query ) ) {
 692                  $this->insert_id = mysql_insert_id( $dbh );
 693              }
 694              // Return number of rows affected
 695              $return_val = $this->rows_affected;
 696          } else {
 697              $i = 0;
 698              while ( $i < @mysql_num_fields( $this->result ) ) {
 699                  $this->col_info[$i] = @mysql_fetch_field( $this->result );
 700                  $i++;
 701              }
 702              $num_rows = 0;
 703              while ( $row = @mysql_fetch_object( $this->result ) ) {
 704                  $this->last_result[$num_rows] = $row;
 705                  $num_rows++;
 706              }
 707  
 708              @mysql_free_result( $this->result );
 709  
 710              // Log number of rows the query returned
 711              $this->num_rows = $num_rows;
 712  
 713              // Return number of rows selected
 714              $return_val = $this->num_rows;
 715          }
 716  
 717          return $return_val;
 718      }
 719  
 720      /**
 721       * Insert a row into a table.
 722       *
 723       * <code>
 724       * wpdb::insert( 'table', array( 'column' => 'foo', 'field' => 1337 ), array( '%s', '%d' ) )
 725       * </code>
 726       *
 727       * @since 1.0
 728       * @see bpdb::prepare()
 729       *
 730       * @param string $table table name
 731       * @param array $data Data to insert (in column => value pairs).  Both $data columns and $data values should be "raw" (neither should be SQL escaped).
 732       * @param array|string $format (optional) An array of formats to be mapped to each of the value in $data.  If string, that format will be used for all of the values in $data.  A format is one of '%d', '%s' (decimal number, string).  If omitted, all values in $data will be treated as strings.
 733       * @return int|false The number of rows inserted, or false on error.
 734       */
 735  	function insert( $table, $data, $format = null )
 736      {
 737          $formats = $format = (array) $format;
 738          $fields = array_keys( $data );
 739          $formatted_fields = array();
 740          foreach ( $fields as $field ) {
 741              if ( !empty( $format ) ) {
 742                  $form = ( $form = array_shift( $formats ) ) ? $form : $format[0];
 743              } elseif ( isset( $this->field_types[$field] ) ) {
 744                  $form = $this->field_types[$field];
 745              } elseif ( is_null( $data[$field] ) ) {
 746                  $form = 'NULL';
 747                  unset( $data[$field] );
 748              } else {
 749                  $form = '%s';
 750              }
 751              $formatted_fields[] = $form;
 752          }
 753          $sql = "INSERT INTO `$table` (`" . implode( '`,`', $fields ) . "`) VALUES (" . implode( ",", $formatted_fields ) . ")";
 754          return $this->query( $this->prepare( $sql, $data ) );
 755      }
 756  
 757      /**
 758       * Update a row in the table
 759       *
 760       * <code>
 761       * wpdb::update( 'table', array( 'column' => 'foo', 'field' => 1337 ), array( 'ID' => 1 ), array( '%s', '%d' ), array( '%d' ) )
 762       * </code>
 763       *
 764       * @since 1.0
 765       * @see bpdb::prepare()
 766       *
 767       * @param string $table table name
 768       * @param array $data Data to update (in column => value pairs).  Both $data columns and $data values should be "raw" (neither should be SQL escaped).
 769       * @param array $where A named array of WHERE clauses (in column => value pairs).  Multiple clauses will be joined with ANDs.  Both $where columns and $where values should be "raw".
 770       * @param array|string $format (optional) An array of formats to be mapped to each of the values in $data.  If string, that format will be used for all of the values in $data.  A format is one of '%d', '%s' (decimal number, string).  If omitted, all values in $data will be treated as strings.
 771       * @param array|string $format_where (optional) An array of formats to be mapped to each of the values in $where.  If string, that format will be used for all of  the items in $where.  A format is one of '%d', '%s' (decimal number, string).  If omitted, all values in $where will be treated as strings.
 772       * @return int|false The number of rows updated, or false on error.
 773       */
 774  	function update( $table, $data, $where, $format = null, $where_format = null )
 775      {
 776          if ( !is_array( $where ) ) {
 777              return false;
 778          }
 779  
 780          $formats = $format = (array) $format;
 781          $bits = $wheres = array();
 782          foreach ( (array) array_keys( $data ) as $field ) {
 783              if ( !empty( $format ) ) {
 784                  $form = ( $form = array_shift( $formats ) ) ? $form : $format[0];
 785              } elseif ( isset( $this->field_types[$field] ) ) {
 786                  $form = $this->field_types[$field];
 787              } elseif ( is_null( $data[$field] ) ) {
 788                  $form = 'NULL';
 789                  unset( $data[$field] );
 790              } else {
 791                  $form = '%s';
 792              }
 793              $bits[] = "`$field` = {$form}";
 794          }
 795  
 796          $where_formats = $where_format = (array) $where_format;
 797          foreach ( (array) array_keys( $where ) as $field ) {
 798              if ( !empty( $where_format ) ) {
 799                  $form = ( $form = array_shift( $where_formats ) ) ? $form : $where_format[0];
 800              } elseif ( isset( $this->field_types[$field] ) ) {
 801                  $form = $this->field_types[$field];
 802              } elseif ( is_null( $where[$field] ) ) {
 803                  unset( $where[$field] );
 804                  $wheres[] = "`$field` IS NULL";
 805                  continue;
 806              } else {
 807                  $form = '%s';
 808              }
 809              $wheres[] = "`$field` = {$form}";
 810          }
 811  
 812          $sql = "UPDATE `$table` SET " . implode( ', ', $bits ) . ' WHERE ' . implode( ' AND ', $wheres );
 813          return $this->query( $this->prepare( $sql, array_merge( array_values( $data ), array_values( $where ) ) ) );
 814      }
 815  
 816      /**
 817       * Retrieve one variable from the database.
 818       *
 819       * Executes a SQL query and returns the value from the SQL result.
 820       * If the SQL result contains more than one column and/or more than one row, this function returns the value in the column and row specified.
 821       * If $query is null, this function returns the value in the specified column and row from the previous SQL result.
 822       *
 823       * @since 1.0
 824       *
 825       * @param string|null $query SQL query.  If null, use the result from the previous query.
 826       * @param int $x (optional) Column of value to return.  Indexed from 0.
 827       * @param int $y (optional) Row of value to return.  Indexed from 0.
 828       * @return string Database query result
 829       */
 830  	function get_var( $query=null, $x = 0, $y = 0 )
 831      {
 832          $this->func_call = "\$db->get_var(\"$query\",$x,$y)";
 833          if ( $query ) {
 834              $this->query( $query );
 835          }
 836  
 837          // Extract var out of cached results based x,y vals
 838          if ( !empty( $this->last_result[$y] ) ) {
 839              $values = array_values( get_object_vars( $this->last_result[$y] ) );
 840          }
 841  
 842          // If there is a value return it else return null
 843          return ( isset($values[$x]) && $values[$x]!=='' ) ? $values[$x] : null;
 844      }
 845  
 846      /**
 847       * Retrieve one row from the database.
 848       *
 849       * Executes a SQL query and returns the row from the SQL result.
 850       *
 851       * @since 1.0
 852       *
 853       * @param string|null $query SQL query.
 854       * @param string $output (optional) one of ARRAY_A | ARRAY_N | OBJECT constants.  Return an associative array (column => value, ...), a numerically indexed array (0 => value, ...) or an object ( ->column = value ), respectively.
 855       * @param int $y (optional) Row to return.  Indexed from 0.
 856       * @return mixed Database query result in format specifed by $output
 857       */
 858  	function get_row( $query = null, $output = OBJECT, $y = 0 )
 859      {
 860          $this->func_call = "\$db->get_row(\"$query\",$output,$y)";
 861          if ( $query ) {
 862              $this->query( $query );
 863          } else {
 864              return null;
 865          }
 866  
 867          if ( !isset( $this->last_result[$y] ) ) {
 868              return null;
 869          }
 870  
 871          if ( $output == OBJECT ) {
 872              return $this->last_result[$y] ? $this->last_result[$y] : null;
 873          } elseif ( $output == ARRAY_A ) {
 874              return $this->last_result[$y] ? get_object_vars( $this->last_result[$y] ) : null;
 875          } elseif ( $output == ARRAY_N ) {
 876              return $this->last_result[$y] ? array_values( get_object_vars( $this->last_result[$y] ) ) : null;
 877          } else {
 878              $this->print_error( " \$db->get_row(string query, output type, int offset) -- Output type must be one of: OBJECT, ARRAY_A, ARRAY_N" );
 879          }
 880      }
 881  
 882      /**
 883       * Retrieve one column from the database.
 884       *
 885       * Executes a SQL query and returns the column from the SQL result.
 886       * If the SQL result contains more than one column, this function returns the column specified.
 887       * If $query is null, this function returns the specified column from the previous SQL result.
 888       *
 889       * @since 1.0
 890       *
 891       * @param string|null $query SQL query.  If null, use the result from the previous query.
 892       * @param int $x Column to return.  Indexed from 0.
 893       * @return array Database query result.  Array indexed from 0 by SQL result row number.
 894       */
 895  	function get_col( $query = null , $x = 0 )
 896      {
 897          if ( $query ) {
 898              $this->query( $query );
 899          }
 900  
 901          $new_array = array();
 902          // Extract the column values
 903          for ( $i=0; $i < count( $this->last_result ); $i++ ) {
 904              $new_array[$i] = $this->get_var( null, $x, $i );
 905          }
 906          return $new_array;
 907      }
 908  
 909      /**
 910       * Retrieve an entire SQL result set from the database (i.e., many rows)
 911       *
 912       * Executes a SQL query and returns the entire SQL result.
 913       *
 914       * @since 1.0
 915       *
 916       * @param string $query SQL query.
 917       * @param string $output (optional) ane of ARRAY_A | ARRAY_N | OBJECT | OBJECT_K | ARRAY_K constants.  With one of the first three, return an array of rows indexed from 0 by SQL result row number.  Each row is an associative array (column => value, ...), a numerically indexed array (0 => value, ...), or an object. ( ->column = value ), respectively.  With OBJECT_K and ARRAY_K, return an associative array of row objects keyed by the value of each row's first column's value.  Duplicate keys are discarded.
 918       * @return mixed Database query results
 919       */
 920  	function get_results( $query = null, $output = OBJECT ) 
 921      {
 922          $this->func_call = "\$db->get_results(\"$query\", $output)";
 923  
 924          if ( $query ) {
 925              $this->query($query);
 926          } else {
 927              return null;
 928          }
 929  
 930          if ( $output == OBJECT ) {
 931              // Return an integer-keyed array of row objects
 932              return $this->last_result;
 933          } elseif ( $output == OBJECT_K || $output == ARRAY_K ) {
 934              // Return an array of row objects with keys from column 1
 935              // (Duplicates are discarded)
 936              $key = $this->col_info[0]->name;
 937              foreach ( $this->last_result as $row ) {
 938                  if ( !isset( $new_array[ $row->$key ] ) ) {
 939                      $new_array[ $row->$key ] = $row;
 940                  }
 941              }
 942              if ( $output == ARRAY_K ) {
 943                  return array_map( 'get_object_vars', $new_array );
 944              }
 945              return $new_array;
 946          } elseif ( $output == ARRAY_A || $output == ARRAY_N ) {
 947              // Return an integer-keyed array of...
 948              if ( $this->last_result ) {
 949                  $i = 0;
 950                  foreach( $this->last_result as $row ) {
 951                      if ( $output == ARRAY_N ) {
 952                          // ...integer-keyed row arrays
 953                          $new_array[$i] = array_values( get_object_vars( $row ) );
 954                      } else {
 955                          // ...column name-keyed row arrays
 956                          $new_array[$i] = get_object_vars( $row );
 957                      }
 958                      ++$i;
 959                  }
 960                  return $new_array;
 961              }
 962          }
 963      }
 964  
 965      /**
 966       * Retrieve column metadata from the last query.
 967       *
 968       * @since 1.0
 969       *
 970       * @param string $info_type one of name, table, def, max_length, not_null, primary_key, multiple_key, unique_key, numeric, blob, type, unsigned, zerofill
 971       * @param int $col_offset 0: col name. 1: which table the col's in. 2: col's max length. 3: if the col is numeric. 4: col's type
 972       * @return mixed Column Results
 973       */
 974  	function get_col_info( $info_type = 'name', $col_offset = -1 )
 975      {
 976          if ( $this->col_info ) {
 977              if ( $col_offset == -1 ) {
 978                  $i = 0;
 979                  foreach( (array) $this->col_info as $col ) {
 980                      $new_array[$i] = $col->{$info_type};
 981                      $i++;
 982                  }
 983                  return $new_array;
 984              } else {
 985                  return $this->col_info[$col_offset]->{$info_type};
 986              }
 987          }
 988      }
 989  
 990      /**
 991       * Starts the timer, for debugging purposes.
 992       *
 993       * @since 1.0
 994       *
 995       * @return true
 996       */
 997  	function timer_start()
 998      {
 999          $mtime = microtime();
1000          $mtime = explode( ' ', $mtime );
1001          $this->time_start = $mtime[1] + $mtime[0];
1002          return true;
1003      }
1004  
1005      /**
1006       * Stops the debugging timer.
1007       *
1008       * @since 1.0
1009       *
1010       * @return int Total time spent on the query, in milliseconds
1011       */
1012  	function timer_stop()
1013      {
1014          $mtime = microtime();
1015          $mtime = explode( ' ', $mtime );
1016          $time_end = $mtime[1] + $mtime[0];
1017          $time_total = $time_end - $this->time_start;
1018          return $time_total;
1019      }
1020  
1021      /**
1022       * Wraps errors in a nice header and footer and dies.
1023       *
1024       * Will not die if bpdb::$show_errors is true
1025       *
1026       * @since 1.0
1027       *
1028       * @param string $message
1029       * @return false|void
1030       */
1031  	function bail( $message )
1032      {
1033          if ( !$this->show_errors ) {
1034              if ( class_exists( 'WP_Error' ) )
1035                  $this->error = new WP_Error( '500', $message );
1036              else
1037                  $this->error = $message;
1038              return false;
1039          }
1040          backpress_die( $message );
1041      }
1042  
1043      /**
1044       * Whether or not MySQL database is at least the required minimum version.
1045       *
1046       * @since 1.0
1047       *
1048       * @return WP_Error
1049       */
1050  	function check_database_version( $dbh_or_table = false )
1051      {
1052          // Make sure the server has MySQL 4.0
1053          if ( version_compare( $this->db_version( $dbh_or_table ), '4.0.0', '<' ) ) {
1054              return new WP_Error( 'database_version', BPDB__DB_VERSION_ERROR );
1055          }
1056      }
1057  
1058      /**
1059       * Whether of not the database supports collation.
1060       *
1061       * Called when BackPress is generating the table scheme.
1062       *
1063       * @since 1.0
1064       *
1065       * @return bool True if collation is supported, false if version does not
1066       */
1067  	function supports_collation()
1068      {
1069          return $this->has_cap( 'collation' );
1070      }
1071  
1072      /**
1073       * Generic function to determine if a database supports a particular feature
1074       *
1075       * @since 1.0
1076       *
1077       * @param string $db_cap the feature
1078       * @param false|string|resource $dbh_or_table Which database to test.  False = the currently selected database, string = the database containing the specified table, resource = the database corresponding to the specified mysql resource.
1079       * @return bool
1080       */
1081  	function has_cap( $db_cap, $dbh_or_table = false )
1082      {
1083          $version = $this->db_version( $dbh_or_table );
1084  
1085          switch ( strtolower( $db_cap ) ) {
1086              case 'collation' :
1087              case 'group_concat' :
1088              case 'subqueries' :
1089                  return version_compare( $version, '4.1', '>=' );
1090                  break;
1091  
1092              case 'index_hint_for_join' :
1093                  return version_compare( $version, '5.0', '>=' );
1094                  break;
1095  
1096              case 'index_hint_lists' :
1097              case 'index_hint_for_any' :
1098                  return version_compare( $version, '5.1', '>=' );
1099                  break;
1100          }
1101  
1102          return false;
1103      }
1104  
1105      /**
1106       * The database version number
1107       *
1108       * @since 1.0
1109       *
1110       * @param false|string|resource $dbh_or_table Which database to test. False = the currently selected database, string = the database containing the specified table, resource = the database corresponding to the specified mysql resource.
1111       * @return false|string false on failure, version number on success
1112       */
1113  	function db_version( $dbh_or_table = false )
1114      {
1115          if ( !$dbh_or_table ) {
1116              $dbh =& $this->dbh;
1117          } elseif ( is_resource( $dbh_or_table ) ) {
1118              $dbh =& $dbh_or_table;
1119          } else {
1120              $dbh = $this->db_connect( "DESCRIBE $dbh_or_table" );
1121          }
1122  
1123          if ( $dbh ) {
1124              return preg_replace( '|[^0-9\.]|', '', mysql_get_server_info( $dbh ) );
1125          }
1126          return false;
1127      }
1128  
1129      /**
1130       * Retrieve the name of the function that called bpdb.
1131       *
1132       * Requires PHP 4.3 and searches up the list of functions until it reaches
1133       * the one that would most logically had called this method.
1134       *
1135       * @since 1.0
1136       *
1137       * @return string The name of the calling function
1138       */
1139  	function get_caller()
1140      {
1141          // requires PHP 4.3+
1142          if ( !is_callable( 'debug_backtrace' ) ) {
1143              return '';
1144          }
1145  
1146          $bt = debug_backtrace();
1147          $caller = array();
1148  
1149          $bt = array_reverse( $bt );
1150          foreach ( (array) $bt as $call ) {
1151              if ( @$call['class'] == __CLASS__ ) {
1152                  continue;
1153              }
1154              $function = $call['function'];
1155              if ( isset( $call['class'] ) ) {
1156                  $function = $call['class'] . "->$function";
1157              }
1158              $caller[] = $function;
1159          }
1160          $caller = join( ', ', $caller );
1161  
1162          return $caller;
1163      }
1164  }