Retrieving Last 7 Days' Data Efficiency

When transferring data from SQL Server to MySQL, it's essential to filter out only relevant data. In this case, extracting the last seven days' data is crucial. However, an SQL query provided yielded unexpected results.

Issue: Missing Data

The query, which utilized GETDATE()-7 AND GETDATE() to filter data, retrieved only five days' worth of results. This discrepancy requires exploration.

Solution: Proper Date Calculation

For SQL Server, GETDATE() returns the current date and time. However, calculating seven days ago requires an adjustment to account for time zones and daylight saving time. To resolve this, DATEADD(day,-7, GETDATE()) is employed. DATEADD() adds a specified number of days (in this case, -7) to the current date, ensuring accurate data retrieval up to the last seven complete days.

Therefore, the corrected query should be:

SELECT id, NewsHeadline as news_headline, NewsText as news_text, state CreatedDate as created_on
FROM News
WHERE CreatedDate >= DATEADD(day,-7, GETDATE())

This modified query will effectively capture the desired seven days' worth of data and resolve the discrepancy experienced earlier.