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   1  <?php
   2  /**
   3   * Plugins may load this file to gain access to special helper functions for
   4   * plugin installation. This file is not included by WordPress and it is
   5   * recommended, to prevent fatal errors, that this file is included using
   6   * require_once().
   7   *
   8   * These functions are not optimized for speed, but they should only be used
   9   * once in a while, so speed shouldn't be a concern. If it is and you are
  10   * needing to use these functions a lot, you might experience time outs. If you
  11   * do, then it is advised to just write the SQL code yourself.
  12   *
  13   * You can turn debugging on, by setting $debug to 1 after you include this
  14   * file.
  15   *
  16   * <code>
  17   * check_column('wp_links', 'link_description', 'mediumtext');
  18   * if (check_column($wpdb->comments, 'comment_author', 'tinytext'))
  19   *     echo "ok\n";
  20   *
  21   * $error_count = 0;
  22   * $tablename = $wpdb->links;
  23   * // check the column
  24   * if (!check_column($wpdb->links, 'link_description', 'varchar(255)')) {
  25   *     $ddl = "ALTER TABLE $wpdb->links MODIFY COLUMN link_description varchar(255) NOT NULL DEFAULT '' ";
  26   *     $q = $wpdb->query($ddl);
  27   * }
  28   *
  29   * if (check_column($wpdb->links, 'link_description', 'varchar(255)')) {
  30   *     $res .= $tablename . ' - ok <br />';
  31   * } else {
  32   *     $res .= 'There was a problem with ' . $tablename . '<br />';
  33   *     ++$error_count;
  34   * }
  35   * </code>
  36   *
  37   * @package WordPress
  38   * @subpackage Plugin
  39   */
  40  
  41  /**
  42   * @global bool $wp_only_load_config
  43   * @name $wp_only_load_config
  44   * @var bool
  45   * @since unknown
  46   */
  47  $wp_only_load_config = true;
  48  
  49  /** Load WordPress Bootstrap */
  50  require_once(dirname(dirname(__FILE__)).'/wp-load.php');
  51  
  52  /**
  53   * Turn debugging on or off.
  54   * @global bool|int $debug
  55   * @name $debug
  56   * @var bool|int
  57   * @since unknown
  58   */
  59  $debug = 0;
  60  
  61  if ( ! function_exists('maybe_create_table') ) :
  62  /**
  63   * Create database table, if it doesn't already exist.
  64   *
  65   * @since unknown
  66   * @package WordPress
  67   * @subpackage Plugin
  68   * @uses $wpdb
  69   *
  70   * @param string $table_name Database table name.
  71   * @param string $create_ddl Create database table SQL.
  72   * @return bool False on error, true if already exists or success.
  73   */
  74  function maybe_create_table($table_name, $create_ddl) {
  75      global $wpdb;
  76      foreach ($wpdb->get_col("SHOW TABLES",0) as $table ) {
  77          if ($table == $table_name) {
  78              return true;
  79          }
  80      }
  81      //didn't find it try to create it.
  82      $wpdb->query($create_ddl);
  83      // we cannot directly tell that whether this succeeded!
  84      foreach ($wpdb->get_col("SHOW TABLES",0) as $table ) {
  85          if ($table == $table_name) {
  86              return true;
  87          }
  88      }
  89      return false;
  90  }
  91  endif;
  92  
  93  if ( ! function_exists('maybe_add_column') ) :
  94  /**
  95   * Add column to database table, if column doesn't already exist in table.
  96   *
  97   * @since unknown
  98   * @package WordPress
  99   * @subpackage Plugin
 100   * @uses $wpdb
 101   * @uses $debug
 102   *
 103   * @param string $table_name Database table name
 104   * @param string $column_name Table column name
 105   * @param string $create_ddl SQL to add column to table.
 106   * @return bool False on failure. True, if already exists or was successful.
 107   */
 108  function maybe_add_column($table_name, $column_name, $create_ddl) {
 109      global $wpdb, $debug;
 110      foreach ($wpdb->get_col("DESC $table_name",0) as $column ) {
 111          if ($debug) echo("checking $column == $column_name<br />");
 112  
 113          if ($column == $column_name) {
 114              return true;
 115          }
 116      }
 117      //didn't find it try to create it.
 118      $wpdb->query($create_ddl);
 119      // we cannot directly tell that whether this succeeded!
 120      foreach ($wpdb->get_col("DESC $table_name",0) as $column ) {
 121          if ($column == $column_name) {
 122              return true;
 123          }
 124      }
 125      return false;
 126  }
 127  endif;
 128  
 129  /**
 130   * Drop column from database table, if it exists.
 131   *
 132   * @since unknown
 133   * @package WordPress
 134   * @subpackage Plugin
 135   * @uses $wpdb
 136   *
 137   * @param string $table_name Table name
 138   * @param string $column_name Column name
 139   * @param string $drop_ddl SQL statement to drop column.
 140   * @return bool False on failure, true on success or doesn't exist.
 141   */
 142  function maybe_drop_column($table_name, $column_name, $drop_ddl) {
 143      global $wpdb;
 144      foreach ($wpdb->get_col("DESC $table_name",0) as $column ) {
 145          if ($column == $column_name) {
 146              //found it try to drop it.
 147              $wpdb->query($drop_ddl);
 148              // we cannot directly tell that whether this succeeded!
 149              foreach ($wpdb->get_col("DESC $table_name",0) as $column ) {
 150                  if ($column == $column_name) {
 151                      return false;
 152                  }
 153              }
 154          }
 155      }
 156      // else didn't find it
 157      return true;
 158  }
 159  
 160  /**
 161   * Check column matches criteria.
 162   *
 163   * Uses the SQL DESC for retrieving the table info for the column. It will help
 164   * understand the parameters, if you do more research on what column information
 165   * is returned by the SQL statement. Pass in null to skip checking that
 166   * criteria.
 167   *
 168   * Column names returned from DESC table are case sensitive and are listed:
 169   *      Field
 170   *      Type
 171   *      Null
 172   *      Key
 173   *      Default
 174   *      Extra
 175   *
 176   * @since unknown
 177   * @package WordPress
 178   * @subpackage Plugin
 179   *
 180   * @param string $table_name Table name
 181   * @param string $col_name Column name
 182   * @param string $col_type Column type
 183   * @param bool $is_null Optional. Check is null.
 184   * @param mixed $key Optional. Key info.
 185   * @param mixed $default Optional. Default value.
 186   * @param mixed $extra Optional. Extra value.
 187   * @return bool True, if matches. False, if not matching.
 188   */
 189  function check_column($table_name, $col_name, $col_type, $is_null = null, $key = null, $default = null, $extra = null) {
 190      global $wpdb, $debug;
 191      $diffs = 0;
 192      $results = $wpdb->get_results("DESC $table_name");
 193  
 194      foreach ($results as $row ) {
 195          if ($debug > 1) print_r($row);
 196  
 197          if ($row->Field == $col_name) {
 198              // got our column, check the params
 199              if ($debug) echo ("checking $row->Type against $col_type\n");
 200              if (($col_type != null) && ($row->Type != $col_type)) {
 201                  ++$diffs;
 202              }
 203              if (($is_null != null) && ($row->Null != $is_null)) {
 204                  ++$diffs;
 205              }
 206              if (($key != null) && ($row->Key  != $key)) {
 207                  ++$diffs;
 208              }
 209              if (($default != null) && ($row->Default != $default)) {
 210                  ++$diffs;
 211              }
 212              if (($extra != null) && ($row->Extra != $extra)) {
 213                  ++$diffs;
 214              }
 215              if ($diffs > 0) {
 216                  if ($debug) echo ("diffs = $diffs returning false\n");
 217                  return false;
 218              }
 219              return true;
 220          } // end if found our column
 221      }
 222      return false;
 223  }
 224  
 225  ?>