database/drivers/mysqli/mysqli_driver.php

   1 <?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
   2 /**
   3  * CodeIgniter
   4  *
   5  * An open source application development framework for PHP 4.3.2 or newer
   6  *
   7  * @package             CodeIgniter
   8  * @author              ExpressionEngine Dev Team
   9  * @copyright   Copyright (c) 2008 - 2009, EllisLab, Inc.
  10  * @license             http://codeigniter.com/user_guide/license.html
  11  * @link                http://codeigniter.com
  12  * @since               Version 1.0
  13  * @filesource
  14  */
  15
  16 // ------------------------------------------------------------------------
  17
  18 /**
  19  * MySQLi Database Adapter Class - MySQLi only works with PHP 5
  20  *
  21  * Note: _DB is an extender class that the app controller
  22  * creates dynamically based on whether the active record
  23  * class is being used or not.
  24  *
  25  * @package             CodeIgniter
  26  * @subpackage  Drivers
  27  * @category    Database
  28  * @author              ExpressionEngine Dev Team
  29  * @link                http://codeigniter.com/user_guide/database/
  30  */
  31 class CI_DB_mysqli_driver extends CI_DB {
  32
  33         var $dbdriver = 'mysqli';
  34
  35         // The character used for escaping
  36         var $_escape_char = '`';
  37
  38         // clause and character used for LIKE escape sequences - not used in MySQL
  39         var $_like_escape_str = '';
  40         var $_like_escape_chr = '';
  41
  42         /**
  43          * The syntax to count rows is slightly different across different
  44          * database engines, so this string appears in each driver and is
  45          * used for the count_all() and count_all_results() functions.
  46          */
  47         var $_count_string = "SELECT COUNT(*) AS ";
  48         var $_random_keyword = ' RAND()'; // database specific random keyword
  49
  50         /**
  51          * Whether to use the MySQL "delete hack" which allows the number
  52          * of affected rows to be shown. Uses a preg_replace when enabled,
  53          * adding a bit more processing to all queries.
  54          */
  55         var $delete_hack = TRUE;
  56
  57         // --------------------------------------------------------------------
  58
  59         /**
  60          * Non-persistent database connection
  61          *
  62          * @access      private called by the base class
  63          * @return      resource
  64          */
  65         function db_connect()
  66         {
  67                 if ($this->port != '')
  68                 {
  69                         return @mysqli_connect($this->hostname, $this->username, $this->password, $this->database, $this->port);
  70                 }
  71                 else
  72                 {
  73                         return @mysqli_connect($this->hostname, $this->username, $this->password, $this->database);
  74                 }
  75
  76         }
  77
  78         // --------------------------------------------------------------------
  79
  80         /**
  81          * Persistent database connection
  82          *
  83          * @access      private called by the base class
  84          * @return      resource
  85          */
  86         function db_pconnect()
  87         {
  88                 return $this->db_connect();
  89         }
  90
  91         // --------------------------------------------------------------------
  92
  93         /**
  94          * Reconnect
  95          *
  96          * Keep / reestablish the db connection if no queries have been
  97          * sent for a length of time exceeding the server's idle timeout
  98          *
  99          * @access      public
 100          * @return      void
 101          */
 102         function reconnect()
 103         {
 104                 if (mysqli_ping($this->conn_id) === FALSE)
 105                 {
 106                         $this->conn_id = FALSE;
 107                 }
 108         }
 109
 110         // --------------------------------------------------------------------
 111
 112         /**
 113          * Select the database
 114          *
 115          * @access      private called by the base class
 116          * @return      resource
 117          */
 118         function db_select()
 119         {
 120                 return @mysqli_select_db($this->conn_id, $this->database);
 121         }
 122
 123         // --------------------------------------------------------------------
 124
 125         /**
 126          * Set client character set
 127          *
 128          * @access      private
 129          * @param       string
 130          * @param       string
 131          * @return      resource
 132          */
 133         function _db_set_charset($charset, $collation)
 134         {
 135                 return @mysqli_query($this->conn_id, "SET NAMES '".$this->escape_str($charset)."' COLLATE '".$this->escape_str($collation)."'");
 136         }
 137
 138         // --------------------------------------------------------------------
 139
 140         /**
 141          * Version number query string
 142          *
 143          * @access      public
 144          * @return      string
 145          */
 146         function _version()
 147         {
 148                 return "SELECT version() AS ver";
 149         }
 150
 151         // --------------------------------------------------------------------
 152
 153         /**
 154          * Execute the query
 155          *
 156          * @access      private called by the base class
 157          * @param       string  an SQL query
 158          * @return      resource
 159          */
 160         function _execute($sql)
 161         {
 162                 $sql = $this->_prep_query($sql);
 163                 $result = @mysqli_query($this->conn_id, $sql);
 164                 return $result;
 165         }
 166
 167         // --------------------------------------------------------------------
 168
 169         /**
 170          * Prep the query
 171          *
 172          * If needed, each database adapter can prep the query string
 173          *
 174          * @access      private called by execute()
 175          * @param       string  an SQL query
 176          * @return      string
 177          */
 178         function _prep_query($sql)
 179         {
 180                 // "DELETE FROM TABLE" returns 0 affected rows This hack modifies
 181                 // the query so that it returns the number of affected rows
 182                 if ($this->delete_hack === TRUE)
 183                 {
 184                         if (preg_match('/^\s*DELETE\s+FROM\s+(\S+)\s*$/i', $sql))
 185                         {
 186                                 $sql = preg_replace("/^\s*DELETE\s+FROM\s+(\S+)\s*$/", "DELETE FROM \\1 WHERE 1=1", $sql);
 187                         }
 188                 }
 189
 190                 return $sql;
 191         }
 192
 193         // --------------------------------------------------------------------
 194
 195         /**
 196          * Begin Transaction
 197          *
 198          * @access      public
 199          * @return      bool
 200          */
 201         function trans_begin($test_mode = FALSE)
 202         {
 203                 if ( ! $this->trans_enabled)
 204                 {
 205                         return TRUE;
 206                 }
 207
 208                 // When transactions are nested we only begin/commit/rollback the outermost ones
 209                 if ($this->_trans_depth > 0)
 210                 {
 211                         return TRUE;
 212                 }
 213
 214                 // Reset the transaction failure flag.
 215                 // If the $test_mode flag is set to TRUE transactions will be rolled back
 216                 // even if the queries produce a successful result.
 217                 $this->_trans_failure = ($test_mode === TRUE) ? TRUE : FALSE;
 218
 219                 $this->simple_query('SET AUTOCOMMIT=0');
 220                 $this->simple_query('START TRANSACTION'); // can also be BEGIN or BEGIN WORK
 221                 return TRUE;
 222         }
 223
 224         // --------------------------------------------------------------------
 225
 226         /**
 227          * Commit Transaction
 228          *
 229          * @access      public
 230          * @return      bool
 231          */
 232         function trans_commit()
 233         {
 234                 if ( ! $this->trans_enabled)
 235                 {
 236                         return TRUE;
 237                 }
 238
 239                 // When transactions are nested we only begin/commit/rollback the outermost ones
 240                 if ($this->_trans_depth > 0)
 241                 {
 242                         return TRUE;
 243                 }
 244
 245                 $this->simple_query('COMMIT');
 246                 $this->simple_query('SET AUTOCOMMIT=1');
 247                 return TRUE;
 248         }
 249
 250         // --------------------------------------------------------------------
 251
 252         /**
 253          * Rollback Transaction
 254          *
 255          * @access      public
 256          * @return      bool
 257          */
 258         function trans_rollback()
 259         {
 260                 if ( ! $this->trans_enabled)
 261                 {
 262                         return TRUE;
 263                 }
 264
 265                 // When transactions are nested we only begin/commit/rollback the outermost ones
 266                 if ($this->_trans_depth > 0)
 267                 {
 268                         return TRUE;
 269                 }
 270
 271                 $this->simple_query('ROLLBACK');
 272                 $this->simple_query('SET AUTOCOMMIT=1');
 273                 return TRUE;
 274         }
 275
 276         // --------------------------------------------------------------------
 277
 278         /**
 279          * Escape String
 280          *
 281          * @access      public
 282          * @param       string
 283          * @param       bool    whether or not the string will be used in a LIKE condition
 284          * @return      string
 285          */
 286         function escape_str($str, $like = FALSE)
 287         {
 288                 if (is_array($str))
 289                 {
 290                         foreach($str as $key => $val)
 291                         {
 292                                 $str[$key] = $this->escape_str($val, $like);
 293                         }
 294
 295                         return $str;
 296                 }
 297
 298                 if (function_exists('mysqli_real_escape_string') AND is_object($this->conn_id))
 299                 {
 300                         $str = mysqli_real_escape_string($this->conn_id, $str);
 301                 }
 302                 elseif (function_exists('mysql_escape_string'))
 303                 {
 304                         $str = mysql_escape_string($str);
 305                 }
 306                 else
 307                 {
 308                         $str = addslashes($str);
 309                 }
 310
 311                 // escape LIKE condition wildcards
 312                 if ($like === TRUE)
 313                 {
 314                         $str = str_replace(array('%', '_'), array('\\%', '\\_'), $str);
 315                 }
 316
 317                 return $str;
 318         }
 319
 320         // --------------------------------------------------------------------
 321
 322         /**
 323          * Affected Rows
 324          *
 325          * @access      public
 326          * @return      integer
 327          */
 328         function affected_rows()
 329         {
 330                 return @mysqli_affected_rows($this->conn_id);
 331         }
 332
 333         // --------------------------------------------------------------------
 334
 335         /**
 336          * Insert ID
 337          *
 338          * @access      public
 339          * @return      integer
 340          */
 341         function insert_id()
 342         {
 343                 return @mysqli_insert_id($this->conn_id);
 344         }
 345
 346         // --------------------------------------------------------------------
 347
 348         /**
 349          * "Count All" query
 350          *
 351          * Generates a platform-specific query string that counts all records in
 352          * the specified database
 353          *
 354          * @access      public
 355          * @param       string
 356          * @return      string
 357          */
 358         function count_all($table = '')
 359         {
 360                 if ($table == '')
 361                 {
 362                         return 0;
 363                 }
 364
 365                 $query = $this->query($this->_count_string . $this->_protect_identifiers('numrows') . " FROM " . $this->_protect_identifiers($table, TRUE, NULL, FALSE));
 366
 367                 if ($query->num_rows() == 0)
 368                 {
 369                         return 0;
 370                 }
 371
 372                 $row = $query->row();
 373                 return (int) $row->numrows;
 374         }
 375
 376         // --------------------------------------------------------------------
 377
 378         /**
 379          * List table query
 380          *
 381          * Generates a platform-specific query string so that the table names can be fetched
 382          *
 383          * @access      private
 384          * @param       boolean
 385          * @return      string
 386          */
 387         function _list_tables($prefix_limit = FALSE)
 388         {
 389                 $sql = "SHOW TABLES FROM ".$this->_escape_char.$this->database.$this->_escape_char;
 390
 391                 if ($prefix_limit !== FALSE AND $this->dbprefix != '')
 392                 {
 393                         $sql .= " LIKE '".$this->escape_like_str($this->dbprefix)."%'";
 394                 }
 395
 396                 return $sql;
 397         }
 398
 399         // --------------------------------------------------------------------
 400
 401         /**
 402          * Show column query
 403          *
 404          * Generates a platform-specific query string so that the column names can be fetched
 405          *
 406          * @access      public
 407          * @param       string  the table name
 408          * @return      string
 409          */
 410         function _list_columns($table = '')
 411         {
 412                 return "SHOW COLUMNS FROM ".$table;
 413         }
 414
 415         // --------------------------------------------------------------------
 416
 417         /**
 418          * Field data query
 419          *
 420          * Generates a platform-specific query so that the column data can be retrieved
 421          *
 422          * @access      public
 423          * @param       string  the table name
 424          * @return      object
 425          */
 426         function _field_data($table)
 427         {
 428                 return "SELECT * FROM ".$table." LIMIT 1";
 429         }
 430
 431         // --------------------------------------------------------------------
 432
 433         /**
 434          * The error message string
 435          *
 436          * @access      private
 437          * @return      string
 438          */
 439         function _error_message()
 440         {
 441                 return mysqli_error($this->conn_id);
 442         }
 443
 444         // --------------------------------------------------------------------
 445
 446         /**
 447          * The error message number
 448          *
 449          * @access      private
 450          * @return      integer
 451          */
 452         function _error_number()
 453         {
 454                 return mysqli_errno($this->conn_id);
 455         }
 456
 457         // --------------------------------------------------------------------
 458
 459         /**
 460          * Escape the SQL Identifiers
 461          *
 462          * This function escapes column and table names
 463          *
 464          * @access      private
 465          * @param       string
 466          * @return      string
 467          */
 468         function _escape_identifiers($item)
 469         {
 470                 if ($this->_escape_char == '')
 471                 {
 472                         return $item;
 473                 }
 474
 475                 foreach ($this->_reserved_identifiers as $id)
 476                 {
 477                         if (strpos($item, '.'.$id) !== FALSE)
 478                         {
 479                                 $str = $this->_escape_char. str_replace('.', $this->_escape_char.'.', $item);
 480
 481                                 // remove duplicates if the user already included the escape
 482                                 return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
 483                         }
 484                 }
 485
 486                 if (strpos($item, '.') !== FALSE)
 487                 {
 488                         $str = $this->_escape_char.str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item).$this->_escape_char;
 489                 }
 490                 else
 491                 {
 492                         $str = $this->_escape_char.$item.$this->_escape_char;
 493                 }
 494
 495                 // remove duplicates if the user already included the escape
 496                 return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
 497         }
 498
 499         // --------------------------------------------------------------------
 500
 501         /**
 502          * From Tables
 503          *
 504          * This function implicitly groups FROM tables so there is no confusion
 505          * about operator precedence in harmony with SQL standards
 506          *
 507          * @access      public
 508          * @param       type
 509          * @return      type
 510          */
 511         function _from_tables($tables)
 512         {
 513                 if ( ! is_array($tables))
 514                 {
 515                         $tables = array($tables);
 516                 }
 517
 518                 return '('.implode(', ', $tables).')';
 519         }
 520
 521         // --------------------------------------------------------------------
 522
 523         /**
 524          * Insert statement
 525          *
 526          * Generates a platform-specific insert string from the supplied data
 527          *
 528          * @access      public
 529          * @param       string  the table name
 530          * @param       array   the insert keys
 531          * @param       array   the insert values
 532          * @return      string
 533          */
 534         function _insert($table, $keys, $values)
 535         {
 536                 return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";
 537         }
 538
 539         // --------------------------------------------------------------------
 540
 541         /**
 542          * Update statement
 543          *
 544          * Generates a platform-specific update string from the supplied data
 545          *
 546          * @access      public
 547          * @param       string  the table name
 548          * @param       array   the update data
 549          * @param       array   the where clause
 550          * @param       array   the orderby clause
 551          * @param       array   the limit clause
 552          * @return      string
 553          */
 554         function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
 555         {
 556                 foreach($values as $key => $val)
 557                 {
 558                         $valstr[] = $key." = ".$val;
 559                 }
 560
 561                 $limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
 562
 563                 $orderby = (count($orderby) >= 1)?' ORDER BY '.implode(", ", $orderby):'';
 564
 565                 $sql = "UPDATE ".$table." SET ".implode(', ', $valstr);
 566
 567                 $sql .= ($where != '' AND count($where) >=1) ? " WHERE ".implode(" ", $where) : '';
 568
 569                 $sql .= $orderby.$limit;
 570
 571                 return $sql;
 572         }
 573
 574
 575         // --------------------------------------------------------------------
 576
 577         /**
 578          * Truncate statement
 579          *
 580          * Generates a platform-specific truncate string from the supplied data
 581          * If the database does not support the truncate() command
 582          * This function maps to "DELETE FROM table"
 583          *
 584          * @access      public
 585          * @param       string  the table name
 586          * @return      string
 587          */
 588         function _truncate($table)
 589         {
 590                 return "TRUNCATE ".$table;
 591         }
 592
 593         // --------------------------------------------------------------------
 594
 595         /**
 596          * Delete statement
 597          *
 598          * Generates a platform-specific delete string from the supplied data
 599          *
 600          * @access      public
 601          * @param       string  the table name
 602          * @param       array   the where clause
 603          * @param       string  the limit clause
 604          * @return      string
 605          */
 606         function _delete($table, $where = array(), $like = array(), $limit = FALSE)
 607         {
 608                 $conditions = '';
 609
 610                 if (count($where) > 0 OR count($like) > 0)
 611                 {
 612                         $conditions = "\nWHERE ";
 613                         $conditions .= implode("\n", $this->ar_where);
 614
 615                         if (count($where) > 0 && count($like) > 0)
 616                         {
 617                                 $conditions .= " AND ";
 618                         }
 619                         $conditions .= implode("\n", $like);
 620                 }
 621
 622                 $limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
 623
 624                 return "DELETE FROM ".$table.$conditions.$limit;
 625         }
 626
 627         // --------------------------------------------------------------------
 628
 629         /**
 630          * Limit string
 631          *
 632          * Generates a platform-specific LIMIT clause
 633          *
 634          * @access      public
 635          * @param       string  the sql query string
 636          * @param       integer the number of rows to limit the query to
 637          * @param       integer the offset value
 638          * @return      string
 639          */
 640         function _limit($sql, $limit, $offset)
 641         {
 642                 $sql .= "LIMIT ".$limit;
 643
 644                 if ($offset > 0)
 645                 {
 646                         $sql .= " OFFSET ".$offset;
 647                 }
 648
 649                 return $sql;
 650         }
 651
 652         // --------------------------------------------------------------------
 653
 654         /**
 655          * Close DB Connection
 656          *
 657          * @access      public
 658          * @param       resource
 659          * @return      void
 660          */
 661         function _close($conn_id)
 662         {
 663                 @mysqli_close($conn_id);
 664         }
 665
 666
 667 }
 668
 669
 670 /* End of file mysqli_driver.php */
 671 /* Location: ./system/database/drivers/mysqli/mysqli_driver.php */