well, i think i did some test before and update from other connect was
allowed in between the query and update. i will test it again with a
time.sleep in between.
On Wednesday, October 17, 2012 3:19:42 AM UTC+8, Niphlod wrote:
>
> Disclaimer: I may be wrong....
> Reading your example code, you are updating a single record.
> If done in a single request, web2py wraps all commands in a transaction.
> In your code, that means that when you want to remove from photolist an
> item of your publication row, that operation is atomic. Why are you
> requesting that no other publication can be updated on that single request ?
>
> On Tuesday, October 16, 2012 9:06:08 PM UTC+2, vince wrote:
>>
>> forget it. it's weird that read lock for mysql is read only, i have to
>> obtain write lock. it seems not possible to block write access only.
>>
>>
>>
>> On Wednesday, October 17, 2012 2:55:49 AM UTC+8, vince wrote:
>>>
>>> i tried to lock table but with error
>>> <class 'gluon.contrib.pymysql.err.InternalError'> (1099, u"Table
>>> 'publication' was locked with a READ lock and can't be updated")
>>>
>>> db.executesql('LOCK TABLE publication READ;')
>>> result = db(db.publication.id==pubid).select()[0]
>>> newlist = result.photo_list
>>> newlist.remove(int(pid))
>>> db(db.publication.id==pubid).update(photo_list=newlist)
>>> db.executesql('UNLOCK TABLES;')
>>>
>>> is it possible to use the same connection?
>>>
>>> On Thursday, October 11, 2012 9:32:14 PM UTC+8, Massimo Di Pierro wrote:
>>>>
>>>> You can try:
>>>>
>>>> db.executesql('LOCK TABLE tablename READ;')
>>>>
>>>>
>>>> http://aarklondatabasetrivia.blogspot.com/2009/04/how-to-lock-and-unlock-tables-in-mysql.html
>>>>
>>>>
>>>> On Thursday, 11 October 2012 01:44:14 UTC-5, vince wrote:
>>>>>
>>>>> can i lock a table as readonly during the transaction? the case is i
>>>>> need to insert a record to table B which is base on the query result of
>>>>> table A, i would like to lock table A as readonly until i finish the
>>>>> insert.
>>>>>
>>>>> i am using mysql at the moment. i know web2py may not have this
>>>>> feature, what is the best way to use mysql's 'lock table' on web2py?
>>>>>
>>>>> thanks in advance,
>>>>> vince
>>>>>
>>>>
--
