On Sep 1, 2009, at 12:46 AM, Doug wrote:
> I have two simple tables - one that defines a statistic, and one
> that hold
> the data for each statistic:
>
> CREATE TABLE Statistic
>
> (
>
> StatID INTEGER PRIMARY KEY,
>
> OwningComputer TEXT NOT NULL
>
> );
>
>
>
> CREATE TABLE StatData
>
> (
>
> StatID INTEGER NOT NULL,
>
> Value INTEGER NOT NULL,
>
> Date INTEGER NOT NULL
>
> );
>
>
>
> and indices.
>
> CREATE INDEX Ind_StatData_StatID on StatData (StatID, Date);
>
> CREATE INDEX Ind_StatData_Date on StatData (Date);
>
>
>
> I'm trying to figure out the best way to find any entries in
> Statistic that
> don't have any corresponding entries in StatData (ie what Statistic is
> defined, but no longer has any data attached).
This might work Ok:
SELECT StatID FROM Statistic WHERE NOT EXISTS (
SELECT 1 FROM StatData WHERE Statistic.StatID=StatData.StatId
);
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