Question

Intro: I have an database with table which contains column with hours, for example

08:30:00
08:45:00
09:30:00
12:20:00
...
18:00:00

the datatype in this column is “time”.
Question: is it possible with SQL to select all hours [ for eg. 10:00:00, 10:30:00, 11:00:00 etc. ] from range 08:00:00 to 18:00:00, which are not on the list?

edit:
Well, after thinking it out, the solution which You [ thanks! ] is not entirely perfect [ well it is perfect with details I gave u 🙂 ]. My application is allowing users to make an appointments which takes half an hour [ in this version of app ]. The column with time I gave u in my first topic is quite optimistic, because I didn’t put cover meetings for hours such as 11:45:00 or 13:05:00, which will end at 12:15:00 and 13:35:00, so I don’t really know from the top which hours I would be able to put in this extra table.

Answer 1

First, create a table T_REF with a column COL_HR with dates that have
all the hours you want to report if not found in the original table.

In MYSQL doing something like this should work

SELECT DATE_FORMAT(COLUMN_NAME, '%H') FROM T_REF
MINUS
SELECT DATE_FORMAT(COLUMN_NAME, '%H') FROM ORIG_TABLE

This will get and compare only the hours and report the ones that are not
in your table (ORIG_TABLE).