CLASSEMENT , plutôt que ROW_NUMBER, car vous voulez que les égalités (celles avec la même valeur B) aient la même valeur de classement :
WITH summary AS (
SELECT t.*,
RANK() OVER (PARTITION BY t.id
ORDER BY t.value_type DESC) AS rank
FROM TABLE t
WHERE t.value_type IN ('A', 'B'))
SELECT s.id,
s.value,
s.value_type,
s.data
FROM summary s
WHERE s.rank = 1
Version non CTE :
SELECT s.id,
s.value,
s.value_type,
s.data
FROM (SELECT t.*,
RANK() OVER (PARTITION BY t.id
ORDER BY t.value_type DESC) AS rank
FROM TABLE t
WHERE t.value_type IN ('A', 'B')) s
WHERE s.rank = 1
WITH test AS (
SELECT 1 AS id, 'B' AS value_type
UNION ALL
SELECT 1, 'B'
UNION ALL
SELECT 1, 'A'
UNION ALL
SELECT 2, 'A'
UNION ALL
SELECT 2, 'A'),
summary AS (
SELECT t.*,
RANK() OVER (PARTITION BY t.id
ORDER BY t.value_type DESC) AS rank
FROM test t)
SELECT *
FROM summary
WHERE rank = 1
J'obtiens :
id value_type rank
----------------------
1 B 1
1 B 1
2 A 1
2 A 1
