class_docstr: Class implementing database connection.
  
  Example
  -------
  >>> AMPLIGRAPH_DATA_HOME='/your/path/to/datasets/'
  >>> # Initialize GraphDataLoader from .csv file
  >>> data = GraphDataLoader("data.csv", backend=SQLiteAdapter)
  >>> # Initialize GraphDataLoader from .txt file using indexer
  >>> # to map entities to integers
  >>> data = GraphDataLoader(AMPLIGRAPH_DATA_HOME + "fb15k/test.txt",
  >>>                        backend=SQLiteAdapter("database.db",
  >>>                        use_indexer=True))
  >>> for elem in data:
  >>>     print(elem)
  >>>     break
  [(1, 1, 2)]
  >>> # Populate the database with raw triples for training
  >>> with SQLiteAdapter("database.db") as backend:
  >>>     backend.populate(AMPLIGRAPH_DATA_HOME + "fb15k/train.txt",
  >>>                      dataset_type="train")
  >>> # Populate the database with indexed triples for training
  >>> with SQLiteAdapter("database.db", use_indexer=True) as backend:
  >>>     backend.populate(AMPLIGRAPH_DATA_HOME + "fb15k/train.txt",
  >>>                      dataset_type="train")
docstr: Connects to the database and execute given query.
  
  Parameters
  ----------
  query: str
       SQLite query to be executed.
  
  Returns
  -------
  output:
       Result of a query with fetchall().
docstr_tok: ["Connects","to","the","database","and","execute","given","query",".","Parameters","--","--","--","--","--","query",":","str","SQLite","query","to","be","executed",".","Returns","--","--","--","-","output",":","Result","of","a","query","with","fetchall","(",")","."]
code: def _execute_query(self, query):
      """Connects to the database and execute given query.
  
      Parameters
      ----------
      query: str
           SQLite query to be executed.
  
      Returns
      -------
      output:
           Result of a query with fetchall().
      """
      with self:
          cursor = self.connection.cursor()
          output = None
          try:
              cursor.execute(query)
              output = cursor.fetchall()
              self.connection.commit()
              if self.verbose:
                  logger.debug(f"Query executed successfully, {query}")
          except Error as e:
              logger.debug(f"Query failed. The error '{e}' occurred")
          return output
  
imports: import logging
  import os
  import sqlite3
  import tempfile
  from sqlite3 import Error
  from urllib.request import pathname2url
  import numpy
  import pandas
  import tensorflow
  from ampligraph.utils.profiling import get_human_readable_size
  from .data_indexer import DataIndexer
label_desc: Use image node_id 10 for calling the SQLiteAdapter obj's underlying member method code with example usage: obj._execute_query(query) and returns: output