How to Fix the Trigger is Invalid and Failed to Re-validation Error in Oracle скачать в хорошем качестве

How to Fix the Trigger is Invalid and Failed to Re-validation Error in Oracle

Discover how to troubleshoot and resolve the "Trigger is invalid and failed to re-validation" error when updating a table in Oracle, with practical examples and solutions. --- This video is based on the question https://stackoverflow.com/q/76864711/ asked by the user 'NgThang2001' ( https://stackoverflow.com/u/22318012/ ) and on the answer https://stackoverflow.com/a/76864787/ provided by the user 'Littlefoot' ( https://stackoverflow.com/u/9097906/ ) 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: Oracle - Trigger is invalid and failed to re-validation 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. --- Introduction: The Challenge with Oracle Triggers When working with Oracle databases, triggers can significantly enhance data manipulation and automation processes. However, they can also lead to frustrating errors if not correctly implemented. One common issue is encountering the error message, "Trigger is invalid and failed to re-validation" during an update operation. In this guide, we'll explore the cause of this error in detail and provide a comprehensive guide to resolve it effectively. We'll break down your code, identify the mistakes, and give you the correct trigger setup. Understanding the Error Message When you see the error "Trigger is invalid and failed to re-validation," it typically means the code in the trigger has compilation issues that prevent Oracle from executing it. This may occur due to missing syntax, incorrect logic, or other code-related problems. Analyze the Trigger Code Let's take a look at the trigger in question: [[See Video to Reveal this Text or Code Snippet]] Upon attempting to execute this trigger, you may find it fails to compile correctly, as indicated by accompanying warnings. Solution Steps for Invalid Trigger Compilation 1. Gather Error Details To diagnose the issue in detail, you can query the user_errors view, which will provide information about the compilation errors. Run the following SQL statement: [[See Video to Reveal this Text or Code Snippet]] This will yield important details about the errors encountered. Look for: Missing semicolon: Often, the lack of a semicolon at the end of statements may cause compilation failures. Improper SQL commands: Ensure your SQL syntax within the trigger adheres to Oracle's regulations. 2. Resolving Specific Errors For instance, if the error indicates a missing semicolon at the end of the insert statement: [[See Video to Reveal this Text or Code Snippet]] 3. Addressing Further Errors After correcting the initial errors, if you encounter: [[See Video to Reveal this Text or Code Snippet]] This indicates that you're trying to update a column referenced in the ON clause, which is prohibited. Update your when matched clause to avoid this issue: Remove the line sb.emp_id = e.emp_id as shown below: [[See Video to Reveal this Text or Code Snippet]] 4. Using Pseudorecords to Fix Mutating Table Error Upon executing the trigger, if you receive the error: [[See Video to Reveal this Text or Code Snippet]] This indicates you're referencing the table currently being modified. Use pseudorecords for accessing data: [[See Video to Reveal this Text or Code Snippet]] Final Version of the Trigger After implementing the above corrections, your trigger should look like this: [[See Video to Reveal this Text or Code Snippet]] Testing the Trigger Now that the trigger is created without errors, let's test it by updating the employees table. [[See Video to Reveal this Text or Code Snippet]] Expected Output After a successful update, you should see the backup reflecting the previous salary correctly in the sal_backup table. Conclusion Fixing the "Trigger is invalid and failed to re-validation" error involves understanding the underlying syntax and operational rules of Oracle triggers. By following the structured steps outlined above, you can effectively resolve the error and ensure your triggers function as intended. Always remember to refer back to error messages, as they often provide valuable insights into what went wrong during compilation.