Oracle: SQL query that returns rows with only numeric values

Question

I have a field (column in Oracle) called X that has values like \"a1b2c3\", \"abc\", \"1ab\", \"123\", \"156\"

how do I write an sql query that returns me only the X

Answer 1

If the only characters to consider are letters then you can do:

select X from myTable where upper(X) = lower(X)

But of course that won't filter out other characters, just letters.