SQL Anywhere: find rows that are +-2 compared to another row - sql

Question

I have the following table:
ID User Form Depth
1 A ABC 2001
1 A XYZ 1001
1 B XYZ 1003
1 B DEF 3001
1 C XYZ 1000
If ID and Form are identical, I need to identify those rows that are +-2 from User A. Using the example above, the script would return:
ID User Form Depth
1 B XYZ 1003
1 C XYZ 1000
I already have a script which identifies rows with identical ID and Form--I just need the other part, but I'm struggling with figuring out the logic. I was hoping there was some kind of DIFF function I could use, but I can't find one for SQL Anywhere.
Does anyone have any suggestions?
Thanks!

Answer 1

If you're looking for the depth to be exactly +/-2 from A's depth:
select t1.*
from mytab t1,
mytab t2
where t1.id = t2.id
and t1.form = t2.form
and t1.user != 'A'
and t2.user = 'A'
and abs(t1.depth - t2.depth) = 2
go
ID User Form Depth
--- ----- ----- -----
1 B XYZ 1003
If you're looking for the depth to be within 2 of A's depth (ie, diff <= 2):
select t1.*
from mytab t1,
mytab t2
where t1.id = t2.id
and t1.form = t2.form
and t1.user != 'A'
and t2.user = 'A'
and abs(t1.depth - t2.depth) <= 2
go
ID User Form Depth
--- ----- ----- -----
1 B XYZ 1003
1 C XYZ 1000
This is pretty basic SQL so while this fiddle was done with MySQL, you should find the queries work in SQLAnywhere, too: sql fiddle

Answer 2

I think you want exists:
select t.*
from t
where t.user <> 'A' and
exists (select 1
from t t2
where t2.form = t.form and t2.id = t.id and
t2.depth between t.depth - 2 and t.depth + 2
);

Answer 3

A quick and dirty generalized method.
Replace #User with whomever you would like to remove.
DECLARE #table TABLE (
ID Int
,[User] VARCHAR(2)
,Form VARCHAR(3)
,Depth INT
)
DECLARE #User VARCHAR(2) = 'A'
INSERT INTO #table (ID , [User], Form, Depth)
VALUES
(1 , 'A' , 'ABC' , 2001),
(1 , 'A' , 'XYZ' , 1001),
(1 , 'B' , 'XYZ' , 1003),
(1 , 'B' , 'DEF' , 3001),
(1 , 'C' , 'XYZ' , 1000)
SELECT t1.ID, t1.[User], t1.Form, t1.Depth , ROW_NUMBER() OVER(ORDER BY t1.ID, t1.[User], t1.Form, t1.Depth) AS [row_number]
INTO #temp
FROM #table as t1
INNER JOIN (
SELECT t.ID, t.Form, COUNT('8') as [count]
FROM #table as t
GROUP BY ID, Form
HAVING COUNT('8') > 1
) as duplicates
ON duplicates.ID = t1.ID
AND duplicates. Form = t1.Form
ORDER BY ID, User, Form, Depth
-- SELECT * FROM #temp
SELECT [row_number] - 2 as value
INTO #range
FROM #temp as t
WHERE t.[User] = #User
--SELECT * FROM #range
INSERT INTO #range
SELECT [row_number] - 1
FROM #temp as t
WHERE t.[User] = #User
INSERT INTO #range
SELECT [row_number] + 1
FROM #temp as t
WHERE t.[User] = #User
INSERT INTO #range
SELECT [row_number] + 2
FROM #temp as t
WHERE t.[User] = #User
SELECT * FROM #temp
WHERE [row_number] IN (SELECT value FROM #range)
DROP TABLE #temp
DROP TABLE #range