The Oracle comparison string is based on the ASCII code, the first letter of the ASCII size comparison if the equivalence is then compared to the next, and so on. The manipulation of strings and numbers is reported as unusual, because different types cannot be compared. Oracle sometimes automatically converts when executing SQL, for example: SELECT * from Chan_customer cc where cc.customer_id = ' 1 '; even if the customer_id is a digital type, it can be traced. However, Oracle distinguishes between characters and numbers by adding non-single quotes.
To verify that the string comparisons in Oracle are compared by ASCII code, make a simple validation example.
Select ASCII (' a '), ASCII (' 888 ') from dual;
Summary: hands-on implementation of the following, the results will be more impressive!
Comparison of the size of strings in Oracle, comparison and operation of strings to numbers