在Oracle SQL中按时间查询数据

Question

I have a table in Oracle in which data is inserted from different sources. In 2014, we discovered that some sources were not inserting the time stamp with the date, we however fixed them and now all sources insert data in proper format, example 05/04/2015 4:30:42 PM

Using a SQL query, we want to divide the data into 3 types, morning shift, evening shift and no shift (for data without the time stamp).

Morning shift will be between 00:00:00 and 14:30:00

Evening shift will be between 14:31:00 and 23:59:00

I have written the query in 2 different ways as follows:

(a)

 CASE
        WHEN TO_DATE(DATEANDTIME,'MM/DD/YYYY HH24:MI:SS') BETWEEN (TO_DATE ('00:00:00', 'HH24:MI:SS')) AND (TO_DATE ('14:30:00', 'HH24:MI:SS'))
        THEN
           'MORNING SHIFT'
        WHEN TO_DATE(DATEANDTIME,'MM/DD/YYYY HH24:MI:SS') BETWEEN (TO_DATE ('14:31:00', 'HH24:MI:SS')) AND  (TO_DATE ('23:59:00', 'HH24:MI:SS'))
        THEN
           'EVENING SHIFT'
        ELSE
          'NO SHIFT'
     END SHIFT

(b)

CASE
        WHEN DATEANDTIME BETWEEN (TO_DATE ('00:00:00', 'HH24:MI:SS')) AND (TO_DATE ('14:30:00', 'HH24:MI:SS'))
        THEN
           'MORNING SHIFT'
        WHEN DATEANDTIME BETWEEN (TO_DATE ('14:31:00', 'HH24:MI:SS')) AND  (TO_DATE ('23:59:00', 'HH24:MI:SS'))
        THEN
           'EVENING SHIFT'
        ELSE
          'NO SHIFT'
     END SHIFT

Query (a) returns an error ORA-01858: a non-numeric character was found where a numeric was expected but Query (b) displays data with everything going to NO SHIFT

Sample data of the table is as follows of the dateandtime field:

05/04/2015 10:43
05/04/2015 16:52
05/04/2015 19:27
11/04/2009

Kindly guide me to the correct query and what am I doing wrong, the same conditions works in TOAD fine.

Answer 1

You can convert the value to a string and do the comparison as strings:

(case when to_char(dateandtime, 'HH24:MI') BETWEEN '00:00' and '14:30'
      then 'MORNING SHIFT'
      when to_char(dateandtime, 'HH24:MI') BETWEEN '14:31' and '23:59'
      then 'EVENING SHIFT'
      else 'NO SHIFT'
 end) as SHIFT