Finding multiple occurrences in SQLite3 database? - sql

Question

I am having trouble with my SQL Query to return all entries in a column which have occurred more than twice.
I have looked at other StackOverflow answers for trying to do this, and whenever I apply the same query to mine it just returns entries where the first character in the entry is the same.
For example, there are around 6 entries in the database which start off with a '-' and it returns all of them even though they are not identical matches.
Would someone be able to tell me where my query is going wrong?
I would have thought that looking for duplicates would be a standard procedure.
Here is the query I am using:
SELECT name FROM subs GROUP BY name HAVING (COUNT(name) > 1);
Here is a sample of the output:
-Johnny-
-Lady_Gaga-
-Randy_Marsh-
AJWesty
All_CAPS
NB: I am looking to find all the usernames in the database that occur more than once.
Thanks in advance!

Answer 1

You could try stripping the dashes off the names column. Here is one way to do that:
SELECT REPLACE(name, '-', '')
FROM subs
GROUP BY REPLACE(name, '-', '')
HAVING (COUNT(name) > 1);
But this approach runs the risk of removing dashes occurring inside a name. To avoid this, we need to do more work:
SELECT
CASE WHEN SUBSTR(name, 1, 1) = '-' AND SUBSTR(name, LENGTH(name), 1) = '-'
THEN SUBSTR(name, 2, LENGTH(name)-2)
ELSE name END AS name
FROM subs
GROUP BY
CASE WHEN SUBSTR(name, 1, 1) = '-' AND SUBSTR(name, LENGTH(name), 1) = '-'
THEN SUBSTR(name, 2, LENGTH(name)-2)
ELSE name END
HAVING COUNT(*) > 1;