check if “it's a number” function in Oracle

Question

I\'m trying to check if a value from a column in an oracle (10g) query is a number in order to compare it. Something like:

select case when ( is_number(myTab         


        

Answer 1

This is a potential duplicate of Finding rows that don't contain numeric data in Oracle. Also see: How can I determine if a string is numeric in SQL?.

Here's a solution based on Michael Durrant's that works for integers.

SELECT foo
FROM bar
WHERE DECODE(TRIM(TRANSLATE(your_number,'0123456789',' ')), NULL, 'number','contains char') = 'number'

Adrian Carneiro posted a solution that works for decimals and others. However, as Justin Cave pointed out, this will incorrectly classify strings like '123.45.23.234' or '131+234'.

SELECT foo
FROM bar
WHERE DECODE(TRIM(TRANSLATE(your_number,'+-.0123456789',' ')), NULL, 'number','contains char') = 'number'

If you need a solution without PL/SQL or REGEXP_LIKE, this may help.