How to Diagnose and Fix the ORA-01804 Error in Oracle

If you are encountering the ORA-01804 error in Oracle, it means that the date format provided is not valid. This error can occur when attempting to insert or update a date value in a table, or when performing date arithmetic in a query.

Diagnosing the ORA-01804 Error

When diagnosing the ORA-01804 error, it’s important to first identify the specific query or operation that is causing the error. This can be done by reviewing the error message and the context in which it occurs. For example, if the error is occurring during an insert or update operation, check the date format being used and the column data type.

Additionally, it’s important to consider the session’s NLS_DATE_FORMAT setting, as this can affect the interpretation of date values in SQL statements. You can check the current NLS_DATE_FORMAT setting by running the following query:


If the NLS_DATE_FORMAT setting is not compatible with the date format being used in the query, it can result in the ORA-01804 error.

Fixing the ORA-01804 Error

Once the cause of the ORA-01804 error has been identified, there are several potential solutions to consider:

1. Adjusting the Date Format

If the error is occurring due to an incompatible date format, you can adjust the date format being used in the query to match the NLS_DATE_FORMAT setting. For example, if the NLS_DATE_FORMAT is set to ‘DD-MON-YYYY’, ensure that date values in the query are formatted accordingly.

2. Changing the NLS_DATE_FORMAT Setting

If the date format used in the query cannot be adjusted, you can consider changing the NLS_DATE_FORMAT setting for the session. This can be done using the following SQL statement:


Be aware that changing the NLS_DATE_FORMAT setting can impact other date-related operations in the session, so it’s important to consider the broader implications of this change.

3. Using TO_DATE Function

If the error is occurring due to date arithmetic or manipulation, ensure that date values are properly converted using the TO_DATE function. For example:

SELECT TO_DATE('2022-01-01', 'YYYY-MM-DD') FROM dual;

Using the TO_DATE function ensures that the date format is explicitly specified, avoiding potential compatibility issues.


The ORA-01804 error in Oracle can be caused by incompatible date formats or NLS settings. By diagnosing the specific cause of the error and considering the potential solutions outlined above, you can effectively address and resolve the issue.

For more information on date formats and NLS settings in Oracle, refer to the official Oracle documentation or consult with a database administrator or Oracle support.

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