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SQL function: Detecting Changes Between Two Dates in DB2 SQL

Published On: 16. November 2024Last Updated: 16. November 2024Categories: Db2 LUW, Dev+OpsTags: , , 1,1 min readViews: 85

The XMP_DATE_DIFFS function is a simple yet powerful tool designed to identify differences between two dates. By comparing specific components—day, month, and year—it returns a concise summary of changes. This function is particularly useful for scenarios requiring a quick analysis of whether and how two dates differ.

How It Works

  1. The function compares the day, month, and year components of two input dates.
  2. It assigns a value of 1 if there is a change in any of these components.
  3. If multiple components differ (e.g., both the day and month), the function sums these individual changes, resulting in a total value greater than 1.
  4. A special condition ensures that only a significant year change (over 99 years) is counted.

Input:

  • d1: The first date.
  • d2: The second date.

Output:

  • A small integer value:
    • 1: Indicates a change in any single component (day, month, or year).
    • >1: Indicates changes in multiple components.

Benefits:

  • Efficient Comparison: Instantly spot differences in date components.
  • Granular Control: Accounts for year changes over a significant range (greater than 99 years).
  • Versatile Applications: Ideal for date validations, tracking temporal changes, or creating summary reports.

Example:

d1 d2 Output Explanation
2024-11-01 2024-11-02 1 Change in day only.
2024-11-01 2024-12-01 1 Change in month only.
2024-11-01 2124-11-01 1 Significant year change (>99).
2024-11-01 2124-12-02 3 Changes in year, month, and day.
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