Resolving the numeric or value error in PL/SQL Procedures

Encountering a `numeric or value error` in your PL/SQL procedures? Learn how to troubleshoot and resolve this common issue, ensuring your OUT parameters are managed correctly.
---

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding the Numeric or Value Error in PL/SQL

If you are working with Oracle PL/SQL and you encounter the dreaded ORA-06502: PL/SQL: numeric or value error, you are not alone. This error is common among developers who are trying to manage variable data types within stored procedures. In this post, we'll explore a specific scenario where an OUT parameter in a package procedure throws this error and how to effectively resolve the issue.

The Problem

In your procedure, you have defined an OUT parameter p_return_msg as a VARCHAR2. However, when you attempt to assign a string value to it, you receive the following error messages:

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

This error specifically indicates that the buffer allocated for your output parameter is too small to hold the string being assigned, leading to a failure when the assignment is attempted.

Key Points to Note

Problematic Assignments: Assigning values exceeding the declared size will generate an error.

Calling Environment: The issue might also stem from the environment calling the PL/SQL procedure (for example, C# code), which does not allocate enough space for the OUT variable.

Diagnosing the Issue

When faced with this error, the first step is to confirm the specific line of code that is causing the issue. In your case, the assignments like:

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

and

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

need to be re-evaluated in light of how the OUT parameter is being handled in the calling code.

Example Procedure

Consider the following procedure example that highlights this issue:

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

If you try to call this procedure with a variable that isn’t correctly sized, such as:

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

You will receive the same ORA-06502 error because l_msg cannot hold the string being assigned (more than 5 characters).

Correcting the Variable Size

To fix the issue, ensure that the variable you are using to capture the OUT parameter has adequate length. Changing the declaration to:

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

This adjustment will allow the program to execute successfully, outputting the message without errors.

Solution in C# Environment

In your specific situation, it sounds like the variable being used in C# to receive the output value is not declared properly. Ensure that your code creates the Oracle parameter with sufficient capacity:

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

This line should correctly allocate the buffer to accommodate longer strings that your procedure might return.

Conclusion

In summary, the numeric or value error often arises from a mismatch in expected and actual variable sizes, especially with OUT parameters in PL/SQL. Always ensure:

The variable intended to receive the OUT parameter is appropriately sized to encompass the data potentially returned.

Validate that calling environments (like applications connecting to your database) also allocate the necessary parameters accordingly.

With these measures, you can effectively handle and rectify these common errors in your PL/SQL procedures.

If you have any further questions or specific scenarios you'd like us to address, feel free to reach out in the comments!