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Learn how to efficiently compare strings in Access to identify differences in course properties, including guest access settings.
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How to Easily Compare Two Strings in Access

Managing a Virtual Learning Environment (VLE) can be challenging, especially when you're tasked with ensuring that properties such as guest access are consistent across course copies that change from year to year. If you've stumbled upon a problem where different course IDs share similar properties, you’re not alone.

In this guide, we'll walk through how to effectively compare two strings in Access to help you identify discrepancies in course properties, specifically focusing on the allow_guest_access attribute of your courses.

Understanding the Problem

In your case, you have a substantial list of courses, and each course has a unique identifier (ID). Every academic year, a new version of a course is created, and it retains the same content and properties but with a different ID.

For example, you have a current course with the ID I3132-CHEN-10011-1211-1SE-016651 and a past course with the ID I3132-CHEN-10011-1201-1SE-016651.

The issue here is that while the allow_guest_access setting for the past course is Yes (Y), the current course is set to No (N).

Key Requirements

You need to identify the courses where there is a difference in the allow_guest_access property between the current and past courses. The properties of interest can be found in the two tables (Current and Past) that have the same course-related keys.

Solution: SQL Query for String Comparison

To solve the problem of comparing these two strings in Access, the solution lies in crafting an accurate SQL query. Here's how to do it:

SQL Structure: You would typically leverage JOIN statements in SQL to bring together the relevant fields from both tables.

Comparison Logic: Use the Mid() function to isolate the significant parts of the course IDs you are comparing. The goal is to match the strings excluding the parts that change from year to year.

Here’s the SQL code you'll want to utilize:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Query

INNER JOIN: This clause combines rows from the Current and Past tables that satisfy the specified conditions.

Mid() Function: This is crucial as it extracts specific substrings from the course ID:

Mid(Current.Course_ID, 1, 17) extracts the part of the course ID that is the same in both the current and past courses (from the first character to the 17th).

Mid(Current.Course_ID, 22, 11) does the same for the latter portion of the ID, ensuring we focus only on the unique identifiers.

Difference Check: Finally, the comparison Current.allow_guest_access <> Past.allow_guest_access ensures that only rows where the allow_guest_access values differ will be returned.

Conclusion

By employing this SQL query, you’ll quickly identify which courses have discrepancies in their guest access settings, allowing you to address any issues effectively. Access may not support REGEX, but with the right approach using the Mid() function and JOINs, string comparisons can be tackled efficiently.

If you have further questions or need clarification on this process, feel free to comment below. Happy querying!