ORA-00904: invalid identifier

Hi,

I got ” ORA-00904: invalid identifier ” error in Oracle SQL.

Details of error are as follows.

ORA-00904 string: invalid identifier

Cause: The column name entered is either missing or invalid. Action: Enter a valid column name. A valid column name must begin with a letter, be less than or equal to 30 characters, and consist of only alphanumeric characters and the special characters $, _, and #.

This error is related with the invalid column name or the column name is missing in SQL Statement.

To solve the ORA-00904 error, don’t use the column names as reserverd word of Oracle.

Or check your column name can not be longer than 30 characters.

The column name must be  alphanumeric characters.

If column name includes the special character ( except $, _, #. ), it must be enclosed with double quotation marks

The column name can contain any of the following 3 characters: $, _, #. If the column name includes any other characters, it must be enclosed with double quotation marks

Do you want to learn Oracle SQL, then read the following articles.

Oracle SQL Tutorials For Beginners – Learn Oracle SQL from scratch with Oracle SQL Online Course