SQL: How to select distinct on some columns - sql

Question

I have a table looking something like this:
+---+------------+----------+
|ID | SomeNumber | SomeText |
+---+------------+----------+
|1 | 100 | 'hey' |
|2 | 100 | 'yo' |
|3 | 100 | 'yo' | <- Second occurrence
|4 | 200 | 'ey' |
|5 | 200 | 'hello' |
|6 | 200 | 'hello' | <- Second occurrence
|7 | 300 | 'hey' | <- Single
+---+------------+----------+
I would like to extract the rows where SomeNumber appears more than ones, and SomeNumbers and SomeText are distinct. That means I would like the following:
+---+------------+----------+
|ID | SomeNumber | SomeText |
+---+------------+----------+
|1 | 100 | 'hey' |
|2 | 100 | 'yo' |
|4 | 200 | 'ey' |
|5 | 200 | 'hello' |
+---+------------+----------+
I don't know what to do here.
I need something along the lines:
SELECT t.ID, DISTINCT(t.SomeNumber, t.SomeText) --this is not possible
FROM (
SELECT mt.ID, mt.SomeNumber, mt.SomeText
FROM MyTable mt
GROUP BY mt.SomeNumber, mt.SomeText --can't without mt.ID
HAVING COUNT(*) > 1
)
Any suggestions?

Answer 1

Using a cte with row number and count rows might get you what you need:
Create and populate sample table (Please save us this step in your future questions):
CREATE TABLE MyTable(id int, somenumber int, sometext varchar(10));
INSERT INTO MyTable VALUES
(1,100,'hey'),
(2,100,'yo'),
(3,100,'yo'),
(4,200,'ey'),
(5,200,'hello'),
(6,200,'hello'),
(7,300,'hey');
The query:
;WITH cte as
(
SELECT id,
someNumber,
someText,
ROW_NUMBER() OVER (PARTITION BY someNumber, someText ORDER BY ID) rn,
COUNT(id) OVER (PARTITION BY someNumber) rc
FROM MyTable
)
SELECT id, someNumber, someText
FROM cte
WHERE rn = 1
AND rc > 1
Results:
id someNumber someText
1 100 hey
2 100 yo
4 200 ey
5 200 hello