Check that any given Chado table exists.

This function is necessary because Drupal's db_table_exists() function will not look in any other schema but the one were Drupal is installed

Parameters

$table: The name of the chado table whose existence should be checked.

Return value

TRUE if the table exists in the chado schema and FALSE if it does not.

Related topics

File

tripal_chado/api/tripal_chado.schema.api.inc, line 49

Provides an application programming interface (API) for describing Chado tables.

Code

function chado_table_exists($table) {

  // Get the default database and chado schema.
  global $databases;
  $default_db = $databases['default']['default']['database'];
  $chado_schema = chado_get_schema_name('chado');

  // If we've already lookup up this table then don't do it again, as
  // we don't need to keep querying the database for the same tables.
  if (array_key_exists("chado_tables", $GLOBALS) and 
    array_key_exists($default_db, $GLOBALS["chado_tables"]) and 
    array_key_exists($chado_schema, $GLOBALS["chado_tables"][$default_db]) and 
    array_key_exists($table, $GLOBALS["chado_tables"][$default_db][$chado_schema])) {
    return TRUE;
  }

  $sql = "
    SELECT 1
    FROM information_schema.tables
    WHERE
      table_name = :table_name AND
      table_schema = :chado AND
      table_catalog = :default_db
  ";
  $args = array(
    ':table_name' => $table,
    ':chado' => $chado_schema,
    ':default_db' => $default_db
  );
  $results = db_query($sql, $args);
  $exists = $results->fetchObject();
  if (!$exists) {
    return FALSE;
  }

  // Set this table in the GLOBALS so we don't query for it again the next time.
  $GLOBALS["chado_tables"][$default_db][$chado_schema][$table] = TRUE;
  return TRUE;
}