Question

SELECT NUMTODSINTERVAL(SUM(EXTRACT(HOUR FROM time1)), 'HOUR') +
   NUMTODSINTERVAL(SUM(EXTRACT(MINUTE FROM time1)), 'MINUTE') AS HOURS
   FROM table1 WHERE id1 = '123' AND value1 = 123

我需要对NUMTODSINTERVAL进行NVL并将其转换为＆＃39; 0 00：00：00＆＃39;，因为我需要总计总时数。但是，当值为NULL时，结果都为NULL。我应该怎么做呢？

Answer 1

将time1的每次出现替换为：

NVL(time1,to_date('01/01/0001 00:00:00','dd/mm/yyyy hh24:mi:ss'))

Answer 2

你不能按照你的建议行事：

NVL(time1, TO_DSINTERVAL('0 00:00:00'))

因为它们是不同的数据类型; time1是时间戳，而固定值是间隔。您可以使用时间戳文字：

NVL(time1, TIMESTAMP '1972-01-01 00:00:00')

...但这基本上是@sagi建议的 - 只是使用时间戳文字而不是转换后的字符串。只要时间是午夜，日期部分并不重要，可以是任何事情。

您也可以使用轻微变体;因为你只需要小时/分钟数为零：

SELECT NUMTODSINTERVAL(SUM(NVL(EXTRACT(HOUR FROM time1), 0)), 'HOUR') +
   NUMTODSINTERVAL(SUM(NVL(EXTRACT(MINUTE FROM time1), 0)), 'MINUTE') AS HOURS
FROM table1 WHERE id1 = '123' AND value1 = 123

使用CTE进行快速演示以提供非空值：

WITH table1 (id1, value1, time1) AS (
   SELECT '123', 123, TIMESTAMP '2016-01-01 12:34:56.789'
   FROM dual
)
SELECT NUMTODSINTERVAL(SUM(NVL(EXTRACT(HOUR FROM time1), 0)), 'HOUR') +
   NUMTODSINTERVAL(SUM(NVL(EXTRACT(MINUTE FROM time1), 0)), 'MINUTE') AS HOURS
   FROM table1 WHERE id1 = '123' AND value1 = 123;

HOURS
-----------------------------
+000000000 12:34:00.000000000

并且值为空值：

WITH table1 (id1, value1, time1) AS (
   SELECT '123', 123, CAST(null AS TIMESTAMP)
   FROM dual
)
SELECT NUMTODSINTERVAL(SUM(NVL(EXTRACT(HOUR FROM time1), 0)), 'HOUR') +
   NUMTODSINTERVAL(SUM(NVL(EXTRACT(MINUTE FROM time1), 0)), 'MINUTE') AS HOURS
   FROM table1 WHERE id1 = '123' AND value1 = 123;

HOURS
-----------------------------
+000000000 00:00:00.000000000

如何将NVL转换为NUMTODSINTERVAL

2 个答案: