How to Correctly Group Timestamped Data in MySQL for JSON Output?

Formatting SQL Query Results into JSON Object by Group

When working with timestamped data, it's often necessary to organize the results into a specific format, such as a hierarchical JSON object grouped by month and year.

To achieve this in MySQL, the GROUP BY clause is essential. However, a common pitfall is when the query unintentionally groups results across multiple years. This issue arises when the GROUP BY clause is applied only to the month of the timestamp.

To rectify this, the correct approach is to group the results by both YEAR and MONTH using the following syntax:

GROUP BY YEAR(t.summaryDateTime), MONTH(t.summaryDateTime);

This modification ensures that the query groups rows based on both the year and month, producing results that can be formatted into the desired JSON object structure.

The above is the detailed content of How to Correctly Group Timestamped Data in MySQL for JSON Output?. For more information, please follow other related articles on the PHP Chinese website!