pythonを使用してデータベースを並列に照会する方法

Question

データベース照会には2つの機能があります。別の2つのクエリを仮定して、これらを並列に実行して同じデータベースをクエリする方法と、残りのコードの実行を続ける前に両方の結果が返るのを待つ方法はありますか？ここで

def query1(param1, param2): 
    result = None 
    logging.info("Connecting to database...") 
    try: 
     conn = connect(host=host, port=port, database=db) 
     curs = conn.cursor() 
     curs.execute(query) 
     result = curs 
     curs.close() 
     conn.close() 
    except Exception as e: 
     logging.error("Unable to access database %s" % str(e)) 
    return result 


def query2(param1, param2): 
    result = None 
    logging.info("Connecting to database...") 
    try: 
     conn = connect(host=host, port=port, database=db) 
     curs = conn.cursor() 
     curs.execute(query) 
     result = curs 
     curs.close() 
     conn.close() 
    except Exception as e: 
     logging.error("Unable to access database %s" % str(e))  
    return result 

Answer 1

はあなたが達成しようとしている何をマルチスレッドコードです：

from threading import Thread, Lock 

class DatabaseWorker(Thread): 
    __lock = Lock() 

    def __init__(self, db, query, result_queue): 
     Thread.__init__(self) 
     self.db = db 
     self.query = query 
     self.result_queue = result_queue 

    def run(self): 
     result = None 
     logging.info("Connecting to database...") 
     try: 
      conn = connect(host=host, port=port, database=self.db) 
      curs = conn.cursor() 
      curs.execute(self.query) 
      result = curs 
      curs.close() 
      conn.close() 
     except Exception as e: 
      logging.error("Unable to access database %s" % str(e)) 
     self.result_queue.append(result) 

delay = 1 
result_queue = [] 
worker1 = DatabaseWorker("db1", "select something from sometable", 
     result_queue) 
worker2 = DatabaseWorker("db1", "select something from othertable", 
     result_queue) 
worker1.start() 
worker2.start() 

# Wait for the job to be done 
while len(result_queue) < 2: 
    sleep(delay) 
job_done = True 
worker1.join() 
worker2.join()