扭曲的adbapi:runInteraction last_insert_id() [英] Twisted adbapi: runInteraction last_insert_id()

问题描述

class MySQL(object):

    def __init__(self):
        self.dbpool = adbapi.ConnectionPool(
            'MySQLdb',
            db='dummy',
            user='root',
            passwd='',
            host = 'localhost',
            cp_reconnect = True,
            cursorclass=MySQLdb.cursors.DictCursor,
            charset='utf8',
            use_unicode=True
        )

    def process(self, item):
        query = self.dbpool.runInteraction(self.conditionalInsert, item).addErrback(self.handle_error)        
        return item


    def conditionalInsert(self, tx, item):
        tx.execute("INSERT INTO User (user_name) VALUES (%s)",(name))
        tx.execute("SELECT LAST_INSERT_ID()")
        lastID = getID(tx.fetchone())
        # DO SOMETHING USING lasID
        ...
        ...
    def handle_error(self, e):
        log.err(e)

我们下面第二行对应的lastID插入第一行吗?还是可能来自任何runInteraction线程?

The lastID we the second line below corresponds to insert in the first line ? or it could be from any of the runInteraction threads ?

    tx.execute("INSERT INTO User (user_name) VALUES (%s)",(name))
    tx.execute("SELECT LAST_INSERT_ID()")

推荐答案

最后一个ID将是同一事务中最后插入的行的ID.

The last id will be the last inserted row's id in the same transaction.

我已经通过以下操作对其进行了测试:

I have test it use the following operations:

1. 开始事务并使用runInteraction(...)函数插入一行

1. begin a transaction and insert a row use the runInteraction(...) function

获取最后一个插入ID，例如是18

get the last insert id, e.g. it is 18

在运行交易的功能中睡眠30秒

sleep 30 seconds in the function where transaction runs

使用mysql客户端或phpMyAdmin将一行插入同一表

insert a row to the same table use mysql client or phpMyAdmin

获取步骤4中的最后一个插入ID，例如是19

get the last insert id from step 4, e.g. it is 19

sleeping函数返回并再次使用同一Transaction对象查询最后一个插入ID，最后一个插入ID仍为18

sleeping function returns and query the last insert id use the same Transaction object again, the last insert id is still 18

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