如果为 NULL，则为 0，否则为其他值

Question

我的查询在 Vet_Ben_Code 列中显示空值和数字。我希望所有 NULL 读为 0，所有其他数字保持不变，我该怎么做。这是查询：

SELECT STU.Term_Code,
    STU.PIDM,
    STU.Vet,
    RXR.Vet_Ben_Code

FROM
  (SELECT CST.Term_Code,
    CST.PIDM,
    SPB.Vet

  FROM
    (SELECT Term_Code,
      PIDM

     FROM CHELINK.Combined_Student_Table
     WHERE Term_Code BETWEEN '201170' AND '201670'
    )CST
  INNER JOIN
    (SELECT SPBPERS_PIDM,
      SPBPERS_VETC_FILE_NUMBER Vet

     FROM SATURN.SPBPERS
     WHERE SPBPERS_VETC_FILE_NUMBER LIKE 'Y%'
     OR SPBPERS_VETC_FILE_NUMBER LIKE 'y%'
    )SPB

  ON CST.PIDM = SPB.SPBPERS_PIDM
  )STU

LEFT JOIN
  (SELECT RXRVETN_Term_Code_VA AS Term_Code,
    RXRVETN_PIDM               AS PIDM,
    RXRVETN_Vetc_Code          AS Vet_Ben_Code

  FROM FAISMGR.RXRVETN
  WHERE RXRVETN_Term_Code_VA BETWEEN '201170' AND '201670'
  )RXR

ON STU.Term_Code    = RXR.Term_Code
AND STU. PIDM       = RXR.PIDM

Answer 1

您可以使用NVL：

NVL(col, 0)

或者COALESCE：

COALESCE(col, 0)