Re: Cursor Not Passed Properly Inter-Module

On Tuesday 28 November 2006 04:16 pm, Rich Shepard wrote:
> On Tue, 28 Nov 2006, Adrian Klaver wrote:
> > I am somewhat confused.
>
>    My apologies, Adrian.
>
> > The execute statement that is failing is different then the one you are
> > showing i.e. you show a CREATE TABLE statement and the statement that
> > fails is an INSERT statement. Does the CREATE TABLE succeed ? What
> > happens in OnSavMod? (The part of the code that seems to be failing)
>
>    Let me try to clarify. Yes, the table is created, and the code is
> failing after I enter more data and click the "Save" button. Here's the
> method in the calling module:
>
>    def OnSaveMod(self, event):
>      self.modName = self.tcName.GetValue()
>      self.modDesc = self.tcDesc.GetValue()
>      self.modType = self.rb.GetString(self.rb.GetSelection())
>      self.knowlEng = self.keName.GetValue()
>      self.method = self.agent.GetSelection()
>      DBtools.cur.execute("insert or replace into model (model_name,
> model_desc, \ model_type, keName, agent) values \
>                           (self.modnName, self.modDesc, self.modType, \
>                           self.knowlEng, self.method)")
>      DBtools().SaveDB(self.appData.dbFileName)
>
> and the error message is:
>
> Traceback (most recent call last):
>    File "/data1/eikos/modelPage.py", line 202, in OnSaveMod
>      self.dba = DBtools.cur.execute("insert or replace into model
> (model_name, model_desc, model_type, \
> AttributeError: class DBtools has no attribute 'cur'
>
>    Class DBTools() begins with:
>
> class DBtools:
>    appData = config.appData
>
>    def CreateDB(self, dbFileName):
>      self.con = sqlite3.connect(self.appData.dbFileName)
>      self.cur = self.con.cursor()
>
>    The application sequence is this: I click the "New" button, and
> DBtools.CreateDB is called with the name of the sqlite3 database file (in
> the modName variable, above). So, the database connection and cursor are
> established here.
>
>    Next, I enter some data in the widgets where they are assigned to
> modDesc and the rest. Then I click the "Save" button which calls
> OnSaveMod() that then calls the cursor to execute the insert with the new
> data.
>
>    Does this make it clearer?
>
> Rich
I think I see what is happening. In your first post dba creates an instance of 
DBtools().CreateDB(). This has a cursor associated with via the if statement. 
The cursor executes the CREATE TABLE statement. In the OnSaveMod there is no 
creation of a DBtools instance. Calling DBTools.cur.execute fails because at 
the top level of the class cur=None. With what you have shown cur is only 
available through the CreateDB function.
-- 
Adrian Klaver	
[email protected]