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drupal_get_schema

6 common.inc drupal_get_schema($table = NULL, $rebuild = FALSE)
7 bootstrap.inc drupal_get_schema($table = NULL, $rebuild = FALSE)

Get the schema definition of a table, or the whole database schema.

The returned schema will include any modifications made by any module that implements hook_schema_alter().

Parameters

$table: The name of the table. If not given, the schema of all tables is returned.

$rebuild: If true, the schema will be rebuilt instead of retrieved from the cache.

Related topics

23 calls to drupal_get_schema()

File

drupal/includes/bootstrap.inc, line 2534
Functions that need to be loaded on every Drupal request.

Code

function drupal_get_schema($table = NULL, $rebuild = FALSE) {
  static $schema = array();

  if (empty($schema) || $rebuild) {
    // Try to load the schema from cache.
    if (!$rebuild && $cached = cache_get('schema')) {
      $schema = $cached->data;
    }
    // Otherwise, rebuild the schema cache.
    else {
      $schema = array();
      // Load the .install files to get hook_schema.
      // On some databases this function may be called before bootstrap has
      // been completed, so we force the functions we need to load just in case.
      if (function_exists('module_load_all_includes')) {
        // This function can be called very early in the bootstrap process, so
        // we force the module_list() cache to be refreshed to ensure that it
        // contains the complete list of modules before we go on to call
        // module_load_all_includes().
        module_list(TRUE);
        module_load_all_includes('install');
      }

      require_once DRUPAL_ROOT . '/includes/common.inc';
      // Invoke hook_schema for all modules.
      foreach (module_implements('schema') as $module) {
        // Cast the result of hook_schema() to an array, as a NULL return value
        // would cause array_merge() to set the $schema variable to NULL as well.
        // That would break modules which use $schema further down the line.
        $current = (array) module_invoke($module, 'schema');
        // Set 'module' and 'name' keys for each table, and remove descriptions,
        // as they needlessly slow down cache_get() for every single request.
        _drupal_schema_initialize($current, $module);
        $schema = array_merge($schema, $current);
      }

      drupal_alter('schema', $schema);
      // If the schema is empty, avoid saving it: some database engines require
      // the schema to perform queries, and this could lead to infinite loops.
      if (!empty($schema) && (drupal_get_bootstrap_phase() == DRUPAL_BOOTSTRAP_FULL)) {
        cache_set('schema', $schema);
      }
    }
  }

  if (!isset($table)) {
    return $schema;
  }
  elseif (isset($schema[$table])) {
    return $schema[$table];
  }
  else {
    return FALSE;
  }
}