Oracle does automatic String2number conversion, for String column values! However, for the textual comparisons in SQL, the input must be delimited as a String explicitly: The opposite conversion number2String is not performed automatically, not on the SQL-query level.
I had this query:
select max(acc_num) from ACCOUNTS where acc_num between 1001000 and 1001999;
That one presented a problem: Error: ORA-01722: invalid number
I have just surrounded the "numerical" values, to make them 'Strings', just making them explicitly delimited:
select max(acc_num) from ACCOUNTS where acc_num between '1001000' and '1001999';
...and voilà: It returns the expected result.
edit:
And indeed: the col acc_num
in my table is defined as String
. Although not numerical, the invalid number
was reported. And the explicit delimiting of the string-numbers resolved the problem.
On the other hand, Oracle can treat Strings as numbers. So the numerical operations/functions can be applied on the Strings, and these queries work:
select max(string_column) from TABLE;
select string_column from TABLE where string_column between '2' and 'z';
select string_column from TABLE where string_column > '1';
select string_column from TABLE where string_column <= 'b';
CUSTOMER
? You've only given half the information needed. – Equidistant