Re: beginner's question

I would doubt a simple state GUI would be enough to indicate the query request uniquely. Suppose we have 4 tables:

Person

	ID
	Name

Donation
	PersonID
	Amount
	CharityID

Volunteer
	PersonID
	Hours
	CharityID

Charity
	ID
	Name

Sandy Pittendrigh wrote:
>
> For any schema where any table can (somehow) be connected
> to any other table through a connected path of
> primary_key/foreign pairs, it must be possible for an
> external parsing routine to read the data dictionary and
> construct a connected, directional graph of the entire
> schema.
>
> Given this, and also given an arbitrary collection of GUI
> query screens, where each widget in the query screen can be
> toggled on or off, and where each widget in the query screen
> is associated with a (tablename, column_name, data_type)
> touple, then it must be (is it?) possible for that external
> parsing routine to read the "widget state" of the screen
> and dynamically construct the "foreign_key=primary_key"
> clauses needed to make a logical select statement.
>
> In other words, any query screen that interactively prompts
> for the "SELECT columns" part of a select statement as well
> as the "WHERE constraints" part of the select statement, the
> only hard part left is to add in the "link this table to
> that table" clauses. The programmer who designed the schema
> can do this. But what about a parsing routine that only
> knows the state of the query screen?
>
> --
> /* Sandy Pittendrigh >--oO0>
> * sandy_at_nervana.montana.edu
> * http://nervana.montana.edu/~sandy
> */
 

-- 
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                                                       Kyle Lahnakoski
                                                        (416) 892-7784
                                                      kyle_at_arcavia.com