Hi Massimo,
Thanks for replying.
I am trying to access tables that were already created from definitions
either in the db.py file in the models directory, or the definitions in a
controller function. Please see the code below. Do I have to define all the
tables from the shell prompt to access them, even when they already exist?
If so, do I have to write the whole table definition?
I should also mention that I started with welcome app that web2py comes
with, changed the folder name and then commented out all the code in db.py
in welcome/models before adding the code below.
Thanks once again for your help.
**** The CODE ****
*
*
*db.py*
*
*
db = DAL('mysql://root:passwd@localhost/ultimatumG')
# Table containing teamnames
db.define_table('teams',
Field('teamname', 'string', length=40, required=True,
unique=True, notnull=True),
Field('passwd', 'password'),
Field('role', 'string', length=20, required=True,
default='NA'),
format = '%(teamname)s')
# Table showing the ask amount of the first mover
db.define_table('offerdecisions',
Field('round', 'integer'),
Field('askamount', 'integer'),
Field('payoff', 'integer'),
Field('teamname_id', 'reference teams'))
# Table accept-reject decisions
db.define_table('ardecisions',
Field('round', 'integer'),
Field('acceptorreject', 'string', length=2),
Field('payoff', 'integer'),
Field('teamname_id', 'reference teams'),
Field('offerer_id', 'reference teams'))
# Table containing a list of ultimatum game experiments
db.define_table('experimentlist',
Field('experimentname', 'string', length=40))
In addition to the above tables, the following is created from a controller
function.
*default.py*
*
*
def createteams():
if request.post_vars:
experimentname = request.post_vars.experimentname
numteams = int(float(request.post_vars.numteams))
tablename = "{0}_teams".format(experimentname)
migratetablename = "{0}.table".format(tablename)
db.define_table(tablename,
Field('teamname', 'string', length=40, required=True,
unique=True, notnull=True),
Field('passwd', 'password'),
Field('role', 'string', length=20, required=True,
default='NA'),
format = '%(teamname)s')
teamnames = maketeamnames(numteams)
for tname in teamnames:
db[tablename].update_or_insert(teamname=tname)
return dict()
*
*
On Sunday, September 30, 2012 1:42:48 PM UTC-4, Massimo Di Pierro wrote:
>
> This works for me:
>
> $ python web2py.py -S welcome -N
> >>> db = DAL()
> >>> db.define_table('tablename',Field('name'))
> <Table tablename (id,name)>
> >>> db.tablename.drop()
>
> Are you try to drop a table "tablename" that was not defined?
>
> On Sunday, 30 September 2012 11:55:09 UTC-5, curiouslearn wrote:
>>
>> Recently I created a simple game in web2py for educational purposes. It
>> worked out well, however, for this game I did not make use of a lot of
>> functionality available in web2py; especially the DAL. I used MySQLdb and
>> raw sql queries to do the job. Based on the recommendations here, I have
>> decided to use web2py DAL and other tools provided by web2py to rewrite
>> the game and to create other apps using web2py. I have a few questions as I
>> tried a few things. Before I state those, a million thanks to Massimo for
>> creating web2py; and to Anthony and others who have helped me here to get
>> out of it when I am stuck.
>>
>> Questions about DAL
>> ------------------------------
>>
>> (1) If I am using DAL to create tables, is it true that I should not go
>> and make changes to the database from mysql prompt?
>>
>> For example, I created a table using DAL, then went to mysql prompt and
>> deleted the table. When I tried to run the code again, I kept getting an
>> error saying that "table already exists". I looked up on these forums and
>> there were some suggestions about deleting the .table file related to that
>> table in the databases folder of the application. I did that and still kept
>> getting the same error.
>>
>> (2) In the documentation, there is a suggestion for using
>> db.tablename.truncate() for dropping the table.
>>
>> I tried the following:
>>
>> (a) Enter "python web2py.py -S applicationname". This gives the
>> iPython prompt.
>> (b) Enter db = DAL(DAL('mysql://root:mypasswd@localhost/ultimatumG')
>>
>> At this point, when I enter db.tablename.drop() (where tablename is the
>> name of a table in ultimatumG database) I get an error saying :
>>
>> 'DAL' object has no attribute tablename.
>>
>> How do I make small changes to database? It appears I cannot do them from
>> mysql prompt because that confuses the application and for some reason I am
>> unable to connect from iPython prompt.
>>
>> I am using version 2.0.9 (2012-09-13) of web2py.
>>
>> Thanks for your help.
>>
>>
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