What Is the Equivalent For @@Error In Oracle?

In Oracle, the equivalent for @@error in SQL Server is the SQLCODE function.

SQLCODE returns the error number associated with the last error that occurred in PL/SQL code, similar to how @@error returns the error number in SQL Server.

You can use SQLCODE within an exception block to handle errors in Oracle procedures and functions. This function can help to identify and troubleshoot errors that occur during the execution of PL/SQL code.

How to capture runtime errors in Oracle?

To capture runtime errors in Oracle, you can use the EXCEPTION block in PL/SQL code to handle exceptions. Here is an example of how to capture and handle a runtime error in Oracle:

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DECLARE
  v_number NUMBER;
BEGIN
  v_number := 10 / 0; -- This will raise a division by zero error
EXCEPTION
  WHEN OTHERS THEN
    DBMS_OUTPUT.PUT_LINE('An error occurred: ' || SQLERRM);
END;

In this code snippet, when the division by zero error occurs, the exception handler will catch the error and print out the error message using the SQLERRM function.

You can also log the error information into a log table, file or use the UTL_FILE package to write the error information to a specific file in the exception handler block.

How to recover from an error in a stored procedure in Oracle?

There are several ways to recover from an error in a stored procedure in Oracle. Here are some common techniques:

1. Use exception handling: In your stored procedure, you can use the EXCEPTION block to catch any errors that occur during the execution of the code. You can then handle the error in a way that makes sense for your application, such as logging the error, rolling back any changes that were made, or displaying an error message to the user.
2. Roll back changes: If an error occurs in your stored procedure, you may want to roll back any changes that were made before the error occurred. You can do this using the ROLLBACK statement within your stored procedure.
3. Retry the operation: Depending on the nature of the error, you may be able to simply retry the operation that failed. You can do this by adding logic to your stored procedure that checks for certain conditions and retries the operation if those conditions are met.
4. Handle errors in the calling code: If the error in the stored procedure is critical and cannot be recovered from within the procedure itself, you may need to handle the error in the calling code. This could involve catching the error and handling it appropriately, such as logging the error or displaying a message to the user.

Overall, the best approach to recovering from an error in a stored procedure will depend on the specific situation and the requirements of your application. It is important to thoroughly test your error handling logic to ensure that it works as expected in various scenarios.

How to raise an exception in a SELECT statement in Oracle?

In Oracle, you can raise an exception in a SELECT statement by using the RAISE_APPLICATION_ERROR function. Here's an example:

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SELECT 
    CASE 
        WHEN <condition> THEN <value>
        ELSE RAISE_APPLICATION_ERROR(-20001, 'Custom error message')
    END AS result
FROM your_table;

In this example, if the condition specified in the CASE statement is not met, the SELECT statement will raise a custom error with the message 'Custom error message' and the error code -20001. You can modify the error code and message to fit your specific requirements.

It's important to note that raising an exception in a SELECT statement will abort the query and return the error message, so make sure to handle it appropriately in your application logic.

How to handle exceptions in Oracle stored procedures?

To handle exceptions in Oracle stored procedures, you can use the following methods:

1. RAISE_APPLICATION_ERROR: This procedure allows you to raise a user-defined exception with a custom error message and error code. You can use this procedure to handle specific error conditions in your stored procedure.
2. EXCEPTION block: You can use the EXCEPTION block in your stored procedure to catch and handle specific exceptions. You can specify different handling logic for different types of exceptions using the WHEN clause.
3. SQLCODE and SQLERRM functions: These functions can be used to retrieve the error code and error message associated with the last exception that occurred in the stored procedure. You can use these functions to log the error information or take appropriate action based on the specific error code.
4. PRAGMA EXCEPTION_INIT: You can use this pragma to associate a custom exception code with a specific Oracle error code. This allows you to handle specific Oracle errors in a more controlled manner.

By combining these methods, you can effectively handle exceptions in your Oracle stored procedures and ensure that your code responds appropriately to error conditions.