How to Efficiently Retrieve the Top N Records per Group in Access?

Extracting the Top N Records per Group in Microsoft Access Databases

This guide demonstrates how to efficiently retrieve the top three most recent entries for each user from a Microsoft Access 'Progress' table. The solution employs nested queries for optimal performance.

The primary SELECT statement acts as the outer query, iterating through each unique LoginID within the 'Progress' table. For every LoginID, an inner subquery is executed using the IN operator.

This subquery identifies the three most recent distinct [Date Taken] values for the current LoginID, ordered descending by date. This effectively limits the results to the three latest records per user.

The outer query then filters the 'Progress' table, retaining only records where the [Date Taken] matches those selected by the subquery. This ensures that we retrieve the corresponding data for the top three dates per user.

By nesting these queries, the code efficiently groups data by LoginID and selects the three most recent entries for each group. The final result set is sorted by LoginID and [Date Taken] for easy readability.

This nested query approach is particularly useful when handling scenarios with tied scores or multiple entries on the same date for a given user. It provides a robust and efficient method for retrieving the top N records per group within a Microsoft Access database.

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