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ORA-01722: invalid number tips

Oracle Error Tips by Burleson Consulting


Oracle docs offer this information regarding Oracle ORA-01722:

       ORA-01722 invalid number
Cause: The attempted conversion of a character string to a number failed because the character string was not a valid numeric literal. Only numeric fields or character fields containing numeric data may be used in arithmetic functions or expressions. Only numeric fields may be added to or subtracted from dates.
Action: Check the character strings in the function or expression. Check that they contain only numbers, a sign, a decimal point, and the character "E" or "e" and retry the operation.

Jonathan Gennick provides information regarding Oracle ORA-01722 in conjunction with subqueries and Oracle Optimizer. 

To exhibit how Oracle ORA-01722 is often thrown, this query is given as an example:


Here, from in the FROM clause of a query, the user is attempting to have a subquery of the original query, which is causing Oracle ORA-01722 to be thrown. 

The Oracle ORA-01722 error is thrown with the failure because  of the outer query.  This is because it is trying to test the NUM > 0 condition first because it is assumed it might be more useful. 

Gennick goes on to show that Oracle ORA-01722 is thrown because the Oracle optimizer has re-written the query as:

AND    FLAG = 'N' ;

This throws Oracle ORA-01722 because the re-written query causes the system to convert a non-numeric NUM value of the WHERE clause into numbers.

OraFaq also has notes on Oracle ORA-01722.  Here, it is explained that Oracle ORA-01722 is thrown because a particular string was not able o be converted into a specific valid number when a user attempted to convert a character string. 

There are several possible resolutions to Oracle ORA-01722 in this context:

  • If you are attempting an " INSERT INTO ... VALUES (...) " you need to find out which data item is invalid
  • If you are trying to supply the values in a sub query which is intended to INSERT or UPDATE, you have to dig a little beeper because the character that is throwing ORA-01722 is actually hidden.  You would then need to find the row that contains a non-numeric string.  Then, you should fix or add data to resolve ORA-01722
  • Instead of an INSERT or UPDATE, you attempt a SELECT.  Here, ORA-01722 is thrown most likely because of some implicit conversation in WHERE.  To resolve ORA-01722 in this context, find a numeric and character column which are being compared.

For more information on Oracle ORA-01722 see these links:

ORA-01722 - Oracle DBA Forums

ORA-01722: invalid number



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