Скачать или смотреть Resolving the No Rows Selected Issue in SQL Developer

Discover why you see "no rows selected" in SQL Developer and learn how to fix it with simple steps!
---
This video is based on the question https://stackoverflow.com/q/64487945/ asked by the user 'Timer' ( https://stackoverflow.com/u/13305519/ ) and on the answer https://stackoverflow.com/a/64488698/ provided by the user 'MT0' ( https://stackoverflow.com/u/1509264/ ) 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: No rows selected sql developer

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

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding and Resolving the No Rows Selected Issue in SQL Developer

When working with Oracle SQL Developer, it can be frustrating to perform a query only to see the output stating “no rows selected.” This guide will dissect this common issue, allowing you to understand why it happens and how to effectively address it.

The Problem Explained

Imagine you're connecting to a database as a different user, running a query, and expecting some results from the table, but your output shows “no rows selected.” Here’s an example of the situation:

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

Output:

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

You might wonder, “Why aren’t the data rows I expect appearing?” This situation usually arises from a misunderstanding of how database sessions and commits work in SQL environments.

What Causes “No Rows Selected”?

The primary reason for seeing “no rows selected” stems from how SQL handles transactions and visibility of inserted data across different sessions. Here’s a simplified explanation:

When you insert data into a table in one session, it might not be immediately visible in another session unless it has been committed.

If you do not issue a COMMIT command in the first session after inserting data, the changes remain uncommitted and invisible to other sessions. It's essential to understand that only the session that performs the insert can see this uncommitted data.

Step-by-Step Solution

Now that you understand the underlying cause, let’s go through the steps to resolve this issue:

Step 1: Return to the First Session

If you’ve inserted rows into TABLE1 in another session, return to that session where you performed the insert.

Step 2: Commit Your Changes

Issue the COMMIT statement to make your changes permanent and visible to other sessions.

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

Step 3: Verify in the Second Session

Now switch back to your second session where you were receiving the “no rows selected” message.

Run your query again:

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

You should now see the rows that were inserted in the first session.

Final Thoughts

By comprehending the importance of COMMIT in SQL transactions, you can easily resolve the “no rows selected” problem in SQL Developer. Always remember that data visibility across sessions requires committed changes. Following these steps will not only solve your immediate issue but enhance your working knowledge of SQL manipulation as well.

For any further queries or detailed explanations on SQL practices, feel free to drop your comments below!