How to Indicate No Results in a SQL SELECT Statement

Description:
Learn how to properly handle empty SQL SELECT queries and return user-friendly messages when no results are found in your tables.
---
This video is based on the question https://stackoverflow.com/q/63253588/ asked by the user 'Nick' ( https://stackoverflow.com/u/4408559/ ) and on the answer https://stackoverflow.com/a/63302843/ provided by the user 'dspn' ( https://stackoverflow.com/u/13900375/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How to textually indicate that there are no results in a SQL SELECT?

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/licensing
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Indicate No Results in a SQL SELECT Statement

Working with SQL databases can often present challenges, especially when it comes to handling scenarios where your queries return no results. This often leads to confusion among developers as they may expect a certain output when querying the database. In this post, we will address how to textually indicate that there are no results when performing a SQL SELECT statement, specifically utilizing the CASE statement in SQL Server 2014.

Understanding the Problem

Suppose you are executing a SQL query on a table that may be empty. You want to ensure that when there are no items found, a clear and user-friendly message appears instead of returning just a blank result. Here’s a simplified example of what you might attempt with a CASE statement, only to discover that it does not yield the expected outcome:

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

As shown, this statement does not function as intended when the table has zero non-null rows. This leads to the emptiness of results and no indication that you actually have no data. So how can we rectify this situation?

Solution: Using Conditional Logic for Better Results

The appropriate way to textually indicate that there are no results is to use some conditional logic with an IF statement within your SQL query. Here’s the revised approach:

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

Breakdown of the Solution

Counting Non-Null Rows:

The first part of the query calculates how many non-empty rows exist in the PS_MASTER_ITEM_EC table where INV_ITEM_ID is not null:

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

This helps determine if there are relevant entries to display.

Selecting Valid IDs:

If the count found in the previous step is greater than zero, the next line executes, returning all available INV_ITEM_IDs:

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

Default Message for Empty Table:

If the initial count yields zero, the final part of the query activates, returning a default message to indicate that there are no items:

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

Conclusion

By implementing this conditional approach, you can effectively manage situations where your SQL SELECT queries yield no results. This contributes to a more robust database handling mechanism, improving user experience by providing clear indications of data availability. Instead of leaving users perplexed with empty sets, you can deliver meaningful feedback, guiding them through the query results.

Final Thoughts

Whether you're developing applications or conducting analyses, understanding how to manage empty responses in SQL can save you time and confusion down the line. Keep these strategies in mind next time you find yourself querying an empty table, and ensure that your SQL statements always convey the necessary information!