如何在oracle中度过一天

Question

SELECT 
  TRANSACTION_ID,
  (SELECT CASE WHEN CLOSE_DATE = NULL 
    THEN
      round(sysdate - created_date) 
    ELSE ROUND(CLOSE_DATE - CREATED_DATE)
  ) as NODAYS 
FROM TBL_TRANSACTION 
WHERE CREATED_BY = 101913

Answer 1

你有一个额外的select，你错过了end，你无法用等号运算符测试null - null永远不等于，或者不等于，任何东西，甚至是它自己。

这会让你更进一步：

SELECT 
  TRANSACTION_ID,
  CASE
    WHEN CLOSE_DATE IS NULL 
    THEN round(sysdate - created_date) 
    ELSE ROUND(CLOSE_DATE - CREATED_DATE)
  END as NODAYS 
FROM TBL_TRANSACTION 
WHERE CREATED_BY = 101913

您可以使用NVL()来简化这一点：

SELECT TRANSACTION_ID,
  ROUND(NVL(CLOSE_DATE, SYSDATE) - CREATED_DATE) as NODAYS 
FROM TBL_TRANSACTION 
WHERE CREATED_BY = 101913