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class MigrateSourceDB2 in Migrate 7.2

Implementation of MigrateSource, to handle imports from remote DB2 servers.

Hierarchy

Expanded class hierarchy of MigrateSourceDB2

File

plugins/sources/db2.inc, line 11
Define a MigrateSource class for importing from IBM DB2 databases.

View source 
class MigrateSourceDB2 extends MigrateSource {

  /**
   * Array containing information for connecting to DB2:
   *  database - Database to connect to
   *  username - Username to connect as
   *  password - Password for authentication
   *
   * @var array
   */
  protected $configuration;

  /**
   * The active DB2 connection for this source.
   *
   * @var resource
   */
  protected $connection;
  public function getConnection() {
    return $this->connection;
  }

  /**
   * The SQL query from which to obtain data. Is a string.
   */
  protected $query;

  /**
   * The statement resource from executing the query - traversed to process the
   * incoming data.
   */
  protected $stmt;

  /**
   * Return an options array for DB2 sources.
   *
   * @param boolean $cache_counts
   *  Indicates whether to cache counts of source records.
   */
  public static function options($cache_counts = FALSE) {
    return compact('cache_counts');
  }

  /**
   * Simple initialization.
   */
  public function __construct(array $configuration, $query, $count_query, array $fields, array $options = array()) {
    parent::__construct($options);
    $this->query = $query;
    $this->countQuery = $count_query;
    $this->configuration = $configuration;
    $this->fields = $fields;
  }

  /**
   * Return a string representing the source query.
   *
   * @return string
   */
  public function __toString() {
    return $this->query;
  }

  /**
   * Connect lazily to the DB server.
   */
  protected function connect() {
    if (!isset($this->connection)) {

      // Check for the ibm_db2 extension before attempting to connect with it.
      if (!extension_loaded('ibm_db2')) {
        throw new Exception(t('You must configure the ibm_db2 extension in PHP.'));
      }

      // Connect to db2.
      $this->connection = db2_connect($this->configuration['database'], $this->configuration['username'], $this->configuration['password']);
    }
    if ($this->connection) {
      return TRUE;
    }
    else {
      $e = db2_conn_errormsg();
      throw new Exception($e);
      return FALSE;
    }
  }

  /**
   * Returns a list of fields available to be mapped from the source query.
   *
   * @return array
   *  Keys: machine names of the fields (to be passed to addFieldMapping)
   *  Values: Human-friendly descriptions of the fields.
   */
  public function fields() {

    // The fields are passed to the constructor for this plugin.
    return $this->fields;
  }

  /**
   * Return a count of all available source records.
   */
  public function computeCount() {
    migrate_instrument_start('MigrateSourceDB2 count');

    // Make sure we're connected.
    if ($this
      ->connect()) {

      // Execute the count query.
      $stmt = db2_exec($this->connection, $this->countQuery);

      // If something went wrong, throw an exception with the error message.
      if (!$stmt) {
        $e = db2_stmt_errormsg($stmt);
        throw new Exception($e);
      }

      // Grab the first row as an array.
      $count_array = db2_fetch_array($stmt);

      // The first item in this array will be our count.
      $count = reset($count_array);
    }
    else {

      // Connection failed.
      $count = FALSE;
    }
    migrate_instrument_stop('MigrateSourceDB2 count');
    return $count;
  }

  /**
   * Implementation of MigrateSource::performRewind().
   */
  public function performRewind() {
    migrate_instrument_start('db2_query');

    // Ensure we're connected to the database.
    $this
      ->connect();

    // Execute the query.
    $this->stmt = db2_exec($this->connection, $this->query);

    // Throw an exception with the error message if something went wrong.
    if (!$this->stmt) {
      $e = db2_stmt_errormsg($this->stmt);
      throw new Exception($e);
    }
    migrate_instrument_stop('db2_query');
  }

  /**
   * Implementation of MigrateSource::getNextRow().
   *
   * @return object
   */
  public function getNextRow() {
    return db2_fetch_object($this->stmt);
  }

}

Members

Namesort descending Modifiers Type Description Overrides
MigrateSource::$activeMap protected property The MigrateMap class for the current migration.
MigrateSource::$activeMigration protected property The Migration class currently invoking us, during rewind() and next().
MigrateSource::$cacheCounts protected property Whether this instance should cache the source count.
MigrateSource::$cacheKey protected property Key to use for caching counts.
MigrateSource::$currentKey protected property The primary key of the current row
MigrateSource::$currentRow protected property The current row from the quey
MigrateSource::$highwaterField protected property Information on the highwater mark for the current migration, if any.
MigrateSource::$idList protected property List of source IDs to process.
MigrateSource::$mapRowAdded protected property By default, next() will directly read the map row and add it to the data row. A source plugin implementation may do this itself (in particular, the SQL source can incorporate the map table into the query) - if so, it should set this TRUE so we…
MigrateSource::$multikeySeparator protected property Used in the case of multiple key sources that need to use idlist.
MigrateSource::$numIgnored protected property Number of rows intentionally ignored (prepareRow() returned FALSE)
MigrateSource::$numProcessed protected property Number of rows we've at least looked at. 1
MigrateSource::$originalHighwater protected property The highwater mark at the beginning of the import operation.
MigrateSource::$skipCount protected property Whether this instance should not attempt to count the source.
MigrateSource::$trackChanges protected property If TRUE, we will maintain hashed source rows to determine whether incoming data has changed.
MigrateSource::count public function Return a count of available source records, from the cache if appropriate. Returns -1 if the source is not countable.
MigrateSource::current public function Implementation of Iterator::current() - called when entering a loop iteration, returning the current row
MigrateSource::dataChanged protected function Determine whether this row has changed, and therefore whether it should be processed.
MigrateSource::getCurrentKey public function
MigrateSource::getIgnored public function
MigrateSource::getProcessed public function
MigrateSource::hash protected function Generate a hash of the source row. 3
MigrateSource::key public function Implementation of Iterator::key - called when entering a loop iteration, returning the key of the current row. It must be a scalar - we will serialize to fulfill the requirement, but using getCurrentKey() is preferable.
MigrateSource::next public function Implementation of Iterator::next() - subclasses of MigrateSource should implement getNextRow() to retrieve the next valid source rocord to process.
MigrateSource::prepareRow protected function Give the calling migration a shot at manipulating, and possibly rejecting, the source row.
MigrateSource::resetStats public function Reset numIgnored back to 0.
MigrateSource::rewind public function Implementation of Iterator::rewind() - subclasses of MigrateSource should implement performRewind() to do any class-specific setup for iterating source records.
MigrateSource::valid public function Implementation of Iterator::valid() - called at the top of the loop, returning TRUE to process the loop and FALSE to terminate it
MigrateSourceDB2::$configuration protected property Array containing information for connecting to DB2: database - Database to connect to username - Username to connect as password - Password for authentication
MigrateSourceDB2::$connection protected property The active DB2 connection for this source.
MigrateSourceDB2::$query protected property The SQL query from which to obtain data. Is a string.
MigrateSourceDB2::$stmt protected property The statement resource from executing the query - traversed to process the incoming data.
MigrateSourceDB2::computeCount public function Return a count of all available source records.
MigrateSourceDB2::connect protected function Connect lazily to the DB server.
MigrateSourceDB2::fields public function Returns a list of fields available to be mapped from the source query. Overrides MigrateSource::fields
MigrateSourceDB2::getConnection public function
MigrateSourceDB2::getNextRow public function Implementation of MigrateSource::getNextRow().
MigrateSourceDB2::options public static function Return an options array for DB2 sources.
MigrateSourceDB2::performRewind public function Implementation of MigrateSource::performRewind().
MigrateSourceDB2::__construct public function Simple initialization. Overrides MigrateSource::__construct
MigrateSourceDB2::__toString public function Return a string representing the source query.