如何在pyodbc中同时在n个游标上运行n个进程？

Question

我有一个包含表名的列表，并且假设列表的大小为n。现在我有n台服务器，因此我打开了n个与每个列表相对应的游标，它们也位于另一个列表中。现在，对于每个表，我想调用某个将参数作为这两个列表的函数。

templst = [T1,T2,T3,T4,T5]
curlst = [cur1,cur2,cur3,cur4,cur5]

for x in range(len(templst)):
   for y in range(len(curlst)):
       if( x == y):
           print "extracting of table ",templst[x]
           extract_single(curlst[y], tempst[x]);

我认为以上代码不会并行运行，或者不会同时启动每个游标。

我需要为对应的Ti的curi并行运行extract_single，在此示例中，i变为1到5。怎么做？如何进行并行处理的流程

Answer 1

您可以使用线程来完成这项工作

这只是一个例子：

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()

您可以从这里阅读更多。

https://www.oracle.com/technical-resources/articles/embedded/vasiliev-python-concurrency.html