SQL:Hapus duplikat

Kandidat buku teks untuk fungsi jendela row_number():

;WITH x AS (
    SELECT unique_ID
          ,row_number() OVER (PARTITION BY worker_ID,type_ID ORDER BY date) AS rn
    FROM   tbl
    )
DELETE FROM tbl
FROM   x
WHERE  tbl.unique_ID = x.unique_ID
AND    x.rn > 1

Ini juga menangani situasi di mana satu set penipuan pada (worker_ID,type_ID) berbagi date yang sama .
Lihat demo data.SE .

;WITH x AS (
    SELECT unique_ID
          ,row_number() OVER (PARTITION BY worker_ID,type_ID ORDER BY date) AS rn
    FROM   tbl
    )
DELETE x
WHERE  rn > 1