How to Retrieve the Most Recent Row for a Given ID in a SQL Table?

Identifying the Most Recent Row for a Given ID:

The provided table contains multiple rows with varying signin timestamps for different id values. The objective here is to retrieve the most recent row, based on the signin column, for a specific id value (id=1).

Using MAX() Aggregate and GROUP BY:

One approach to accomplish this is by using the MAX() aggregate function along with a GROUP BY clause. The following query aggregates the maximum signin timestamp for each unique id:

SELECT
  id,
  MAX(signin) AS most_recent_signin
FROM tbl
GROUP BY id;

This query produces a table with two columns: id and most_recent_signin. The most_recent_signin column contains the most recent signin timestamp for each id.

Retrieving the Complete Record:

However, if the goal is to retrieve the complete record (including all columns) for the most recent row with>

SELECT
  tbl.id,
  signin,
  signout
FROM tbl
INNER JOIN (
  SELECT id, MAX(signin) AS maxsign
  FROM tbl
  GROUP BY id
) ms ON tbl.id = ms.id AND signin = maxsign
WHERE tbl.id = 1;

This query performs an INNER JOIN between the tbl table and a subquery (ms) that selects the maximum signin timestamp for each id. It then filters the results to include only the row with>

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