How to Retrieve All Changes Between Two Points in Time

Retrieving all Changes Between Two Points in Time

Write a SQL query to retrieve all changes made to a temporal table between two points in time.

Solution:

-- Retrieve all changes between January 1, 2023, and December 31, 2023.
SELECT EmployeeID, Name, Position, SysStartTime, SysEndTime
FROM Employees
FOR SYSTEM_TIME BETWEEN '2023-01-01' AND '2023-12-31'
ORDER BY SysStartTime;

Explanation:

• Purpose of the Query :
• The goal is to demonstrate how to query all changes made to a table within a specific time range.
• Key Components :
• FOR SYSTEM_TIME BETWEEN: Retrieves all versions of rows valid within the specified range.
• Includes SysStartTime and SysEndTime to track when each version was valid.
• Why Query Changes Over Time? :
• Tracking changes over time provides insights into trends, anomalies, and patterns.
• It supports detailed auditing and analysis.
• Real-World Application :
• In sales systems, querying changes tracks order modifications over a fiscal year.

Additional Notes:

• Use this query for trend analysis or change tracking.
• Order results by SysStartTime to view changes chronologically.
• Important Considerations:
• Ensure that the time range aligns with available data.

For more Practice: Solve these Related Problems:

• Write a SQL query to retrieve all changes made to the Employees table between January 1, 2023, and March 31, 2023.
• Write a SQL query to track modifications in the Products table during the last quarter of 2023.
• Write a SQL query to analyze all updates to the Orders table within a specific fiscal year using temporal data.
• Write a SQL query to fetch all changes to the Inventory table during a promotional period for reporting purposes.

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