Get most recent row for given ID

Swipe right for performance

For quickly courting large datasets, an index on ordering columns can speed up your rendezvous:

CREATE INDEX idx_on_id_signin ON your_table(id, signin DESC);
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To note:

• Two's company, and a composite index is ideal here.
• Descending order in the index aligns your intentions with your queries, like a successful first date.

Ghosting NULLs? Here’s how to sort them out

In contexts where signin holds NULL values, you need a special dating strategy:

SELECT * FROM your_table
WHERE id = 1
ORDER BY signin IS NOT NULL, signin DESC
LIMIT 1;
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• NULLs in SQL are lonelier than non-NULL values, and rank lower.
• Add some spice to your ORDER BY with NULLS LAST or NULLS FIRST - whatever floats your table.

Ensuring deterministic results

Did multiple records text you at the same timestamp? Get one surefire result:

• Entice your search with a unique secondary column in the ORDER BY clause.
• Make sure your SELECT TOP 1 has the qualities you’re looking for to avoid arbitrary results.

Flexibility for various scenarios

Need to get specific columns? Or perhaps you’re into join operations? No worries:

• Subqueries armed with MAX() can specify your needs.
• Join your tables on subqueries for a balanced, healthy data relationship.

SELECT main.id, main.signin, main.signout
FROM your_table main
INNER JOIN (
    SELECT id, MAX(signin) AS MaxSignIn
    FROM your_table
    GROUP BY id
) sub ON main.id = sub.id AND main.signin = sub.MaxSignIn
WHERE main.id = 1; -- Only you, ID 1, forever and always.
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Snack light, not heavy: Slimming data overhead

When you’re on a mission to pluck the most recent row for a given ID, don't overeat:

SELECT id, signin
FROM your_table
WHERE id = 1
ORDER BY signin DESC
LIMIT 1; -- Like the perfect bite, nibble only what you need.
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Your focused query digests exactly what you asked for, ensuring a lean, mean, swift data machine.