Скачать или смотреть Resolving ORA-01722: Invalid Number Error in Oracle SQL

Learn how to fix the ORA-01722: `invalid number` error in Oracle SQL when converting date formats. Our guide walks you through a practical solution.
---
This video is based on the question https://stackoverflow.com/q/68475973/ asked by the user 'JSLover' ( https://stackoverflow.com/u/15316424/ ) and on the answer https://stackoverflow.com/a/68476085/ provided by the user 'Bruno Tardin' ( https://stackoverflow.com/u/14101013/ ) 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: To_Date is giving me ORA-01722: invalid number

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.
---
Resolving ORA-01722: Invalid Number Error in Oracle SQL

Encountering errors while running SQL queries can be frustrating, especially when it disrupts your workflow. One common issue that SQL developers face, particularly in Oracle, is the ORA-01722: invalid number error. This error often indicates a problem with data type conversions, specifically when trying to convert strings to numbers or dates incorrectly. In this guide, we'll unpack this error, and provide a structured solution to resolve it effectively.

Understanding the Problem

The ORA-01722: invalid number error typically surfaces when an attempt is made to convert a string into a number or date in Oracle SQL, but the string cannot be converted due to its format. In this case, the problem arises while converting a LOGOUT column into a date format using the TO_DATE function.

Background Context

You may have a column named LOGOUT in your table, which contains date and time information formatted like this:

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

You were able to successfully use a SQL Server query to handle this column. However, while transitioning this to Oracle syntax, the same logic caused an error. The query you wrote looked like this:

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

This line is throwing an ORA-01722: invalid number because the LOGOUT value is not being recognized as a valid date.

Solution to the ORA-01722 Error

To fix the ORA-01722: invalid number error, you need to ensure that your date format is correctly interpreted by Oracle SQL. Here’s a breakdown:

1. Check the LOGOUT Column Data Type

First, you need to check the data type of your LOGOUT column. If this column is stored in a string format that does not conform to standard date formats, this could lead to conversion issues.

2. Use the Correct Date Format

To avoid conversion issues, you need to ensure that the string representing the date is in the right format that Oracle can interpret as a valid date. If the format of your LOGOUT data doesn't match the expected input for TO_DATE, Oracle will throw an error.

Here’s a correct version of the query that resolves the issue:

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

3. Handle NULL values

Ensure your query is also handling NULL values properly. The NVL function is already doing that by providing a fallback date if LOGOUT is NULL.

4. Running a Test Query

You can test your modification with a simplified query. For example:

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

This should execute without errors and can help you confirm that your date conversion works as expected.

Conclusion

The ORA-01722: invalid number error can be tricky, but understanding the cause and following a structured approach to fix the data conversion can save you a lot of time and frustration. By ensuring that your date values are in the correct format and handling NULLs properly, you can resolve this issue swiftly.

If you encounter further problems or have additional questions about handling dates in Oracle SQL, feel free to reach out or comment below!