ORA-00904: STRING: invalid identifier tips Oracle Error Tips by Donald Burleson

 

Question:  I am running a SQL statement and I get a SQL*Plus error ORA-00904 invalid identifier.

 

Answer: When ORA-00904 occurs, you must enter a valid column name as it is either missing or the one entered is invalid. The "invalid identifier" most common happens when you are referencing an invalid alias in a select statement.  The Oracle docs note this on the ORA-00904 error:

 

ORA-00904 string: invalid identifier

To avoid ORA-00904, column names cannot be a reserved word, and must contain these four criteria to be valid:

• begin with a letter
• be less than or equal to thirty characters
• consist only of alphanumeric and the special characters ($_#); other characters need double quotation marks around them

Another important factor in correcting ORA-00904 is remembering to run catproc.sql

You can also check your trace file to find the particular error which is causing the ORA-00904 to occur. 

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