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   1  <?php
   2  /**
   3   * Plugins may load this file to gain access to special helper functions
   4   * for 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 timeouts.
  11   * If you do, then it is advised to just write the SQL code yourself.
  12   *
  13   *     check_column( 'wp_links', 'link_description', 'mediumtext' );
  14   *
  15   *     if ( check_column( $wpdb->comments, 'comment_author', 'tinytext' ) ) {
  16   *         echo "ok\n";
  17   *     }
  18   *
  19   *     // Check the column.
  20   *     if ( ! check_column( $wpdb->links, 'link_description', 'varchar( 255 )' ) ) {
  21   *         $ddl = "ALTER TABLE $wpdb->links MODIFY COLUMN link_description varchar(255) NOT NULL DEFAULT '' ";
  22   *         $q = $wpdb->query( $ddl );
  23   *     }
  24   *
  25   *     $error_count = 0;
  26   *     $tablename   = $wpdb->links;
  27   *
  28   *     if ( check_column( $wpdb->links, 'link_description', 'varchar( 255 )' ) ) {
  29   *         $res .= $tablename . ' - ok <br />';
  30   *     } else {
  31   *         $res .= 'There was a problem with ' . $tablename . '<br />';
  32   *         ++$error_count;
  33   *     }
  34   *
  35   * @package WordPress
  36   * @subpackage Plugin
  37   */
  38  
  39  /** Load WordPress Bootstrap */
  40  require_once dirname( __DIR__ ) . '/wp-load.php';
  41  
  42  if ( ! function_exists( 'maybe_create_table' ) ) :
  43      /**
  44       * Creates a table in the database if it doesn't already exist.
  45       *
  46       * @since 1.0.0
  47       *
  48       * @global wpdb $wpdb WordPress database abstraction object.
  49       *
  50       * @param string $table_name Database table name.
  51       * @param string $create_ddl SQL statement to create table.
  52       * @return bool True on success or if the table already exists. False on failure.
  53       */
  54  	function maybe_create_table( $table_name, $create_ddl ) {
  55          global $wpdb;
  56  
  57          foreach ( $wpdb->get_col( 'SHOW TABLES', 0 ) as $table ) {
  58              if ( $table === $table_name ) {
  59                  return true;
  60              }
  61          }
  62  
  63          // Didn't find it, so try to create it.
  64          // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- No applicable variables for this query.
  65          $wpdb->query( $create_ddl );
  66  
  67          // We cannot directly tell whether this succeeded!
  68          foreach ( $wpdb->get_col( 'SHOW TABLES', 0 ) as $table ) {
  69              if ( $table === $table_name ) {
  70                  return true;
  71              }
  72          }
  73  
  74          return false;
  75      }
  76  endif;
  77  
  78  if ( ! function_exists( 'maybe_add_column' ) ) :
  79      /**
  80       * Adds column to database table, if it doesn't already exist.
  81       *
  82       * @since 1.0.0
  83       *
  84       * @global wpdb $wpdb WordPress database abstraction object.
  85       *
  86       * @param string $table_name  Database table name.
  87       * @param string $column_name Table column name.
  88       * @param string $create_ddl  SQL statement to add column.
  89       * @return bool True on success or if the column already exists. False on failure.
  90       */
  91  	function maybe_add_column( $table_name, $column_name, $create_ddl ) {
  92          global $wpdb;
  93  
  94          // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Cannot be prepared. Fetches columns for table names.
  95          foreach ( $wpdb->get_col( "DESC $table_name", 0 ) as $column ) {
  96              if ( $column === $column_name ) {
  97                  return true;
  98              }
  99          }
 100  
 101          // Didn't find it, so try to create it.
 102          // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- No applicable variables for this query.
 103          $wpdb->query( $create_ddl );
 104  
 105          // We cannot directly tell whether this succeeded!
 106          // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Cannot be prepared. Fetches columns for table names.
 107          foreach ( $wpdb->get_col( "DESC $table_name", 0 ) as $column ) {
 108              if ( $column === $column_name ) {
 109                  return true;
 110              }
 111          }
 112  
 113          return false;
 114      }
 115  endif;
 116  
 117  /**
 118   * Drops column from database table, if it exists.
 119   *
 120   * @since 1.0.0
 121   *
 122   * @global wpdb $wpdb WordPress database abstraction object.
 123   *
 124   * @param string $table_name  Database table name.
 125   * @param string $column_name Table column name.
 126   * @param string $drop_ddl    SQL statement to drop column.
 127   * @return bool True on success or if the column doesn't exist. False on failure.
 128   */
 129  function maybe_drop_column( $table_name, $column_name, $drop_ddl ) {
 130      global $wpdb;
 131  
 132      // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Cannot be prepared. Fetches columns for table names.
 133      foreach ( $wpdb->get_col( "DESC $table_name", 0 ) as $column ) {
 134          if ( $column === $column_name ) {
 135  
 136              // Found it, so try to drop it.
 137              // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- No applicable variables for this query.
 138              $wpdb->query( $drop_ddl );
 139  
 140              // We cannot directly tell whether this succeeded!
 141              // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Cannot be prepared. Fetches columns for table names.
 142              foreach ( $wpdb->get_col( "DESC $table_name", 0 ) as $column ) {
 143                  if ( $column === $column_name ) {
 144                      return false;
 145                  }
 146              }
 147          }
 148      }
 149  
 150      // Else didn't find it.
 151      return true;
 152  }
 153  
 154  /**
 155   * Checks that database table column matches the criteria.
 156   *
 157   * Uses the SQL DESC for retrieving the table info for the column. It will help
 158   * understand the parameters, if you do more research on what column information
 159   * is returned by the SQL statement. Pass in null to skip checking that criteria.
 160   *
 161   * Column names returned from DESC table are case sensitive and are as listed:
 162   *
 163   *  - Field
 164   *  - Type
 165   *  - Null
 166   *  - Key
 167   *  - Default
 168   *  - Extra
 169   *
 170   * @since 1.0.0
 171   *
 172   * @global wpdb $wpdb WordPress database abstraction object.
 173   *
 174   * @param string $table_name    Database table name.
 175   * @param string $col_name      Table column name.
 176   * @param string $col_type      Table column type.
 177   * @param bool   $is_null       Optional. Check is null.
 178   * @param mixed  $key           Optional. Key info.
 179   * @param mixed  $default_value Optional. Default value.
 180   * @param mixed  $extra         Optional. Extra value.
 181   * @return bool True, if matches. False, if not matching.
 182   */
 183  function check_column( $table_name, $col_name, $col_type, $is_null = null, $key = null, $default_value = null, $extra = null ) {
 184      global $wpdb;
 185  
 186      $diffs = 0;
 187  
 188      // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Cannot be prepared. Fetches columns for table names.
 189      $results = $wpdb->get_results( "DESC $table_name" );
 190  
 191      foreach ( $results as $row ) {
 192  
 193          if ( $row->Field === $col_name ) {
 194  
 195              // Got our column, check the params.
 196              if ( ( null !== $col_type ) && ( $row->Type !== $col_type ) ) {
 197                  ++$diffs;
 198              }
 199              if ( ( null !== $is_null ) && ( $row->Null !== $is_null ) ) {
 200                  ++$diffs;
 201              }
 202              if ( ( null !== $key ) && ( $row->Key !== $key ) ) {
 203                  ++$diffs;
 204              }
 205              if ( ( null !== $default_value ) && ( $row->Default !== $default_value ) ) {
 206                  ++$diffs;
 207              }
 208              if ( ( null !== $extra ) && ( $row->Extra !== $extra ) ) {
 209                  ++$diffs;
 210              }
 211  
 212              if ( $diffs > 0 ) {
 213                  return false;
 214              }
 215  
 216              return true;
 217          } // End if found our column.
 218      }
 219  
 220      return false;
 221  }