Need help solving SQL Oracle Counting Characters - sql

Question

we have a large set of data and the professor is asking us to do the following:
Amy Gray has seven characters in her name. (The space between her first and last name does not count.) J. J. Brown has ten in his name. (The space and periods in J. J. count as characters.) Allison Black-White has eighteen in hers. (The hyphen counts as a character.)
Create a view named A9T4 that will display the size and the total number of students whose combined first and last name has that size. The two column headings should be Name_Size and Students. The rows should be sorted by descending size.
Note: As a simple check of your work, the longest name in A9 has 22 characters and the three shortest names have seven characters.

Answer 1

I used the Oracle DUMP, SUBSTR, and REGEXP_LIKE function to get the count.
http://www.techonthenet.com/oracle/functions/dump.php
http://www.techonthenet.com/oracle/functions/substr.php
http://www.techonthenet.com/oracle/functions/regexp_substr.php
CREATE TABLE SCHEMA1.NAMES (
eval_name VARCHAR2(100 CHAR)
);
insert into SCHEMA1.NAMES values('Amy Gray');
insert into SCHEMA1.NAMES values('J. J. Brown');
insert into SCHEMA1.NAMES values('Allison Black-White');
commit;
select eval_name, REGEXP_SUBSTR(SUBSTR(DUMP(eval_name),11), '^[0-9]*')-1 from SCHEMA1.NAMES;
--returns
Amy Gray 7
J. J. Brown 10
Allison Black-White 18
DUMP('Amy Gray') -- gives us 'Typ=1 Len=8: 65,109,121,32,71,114,97,121'
SUBSTR(DUMP('Amy Gray'),11) -- starts at position eleven, giving us
'8: 65,109,121,32,71,114,97,121'
REGEXP_SUBSTR(SUBSTR(dump('Amy Gray'),11), '^[0-9]*') -- gives us '8', all digits from the beginning of the string '^' to the first non-digit, ':'
--and the -1 removes the expected space between the first and last names.