SQL Like Search - mysql

Question

I am trying run to say find the devices that did not contain 01: in the past 7 days.
I have tried "Where column Not Like '%01:%'" but it just removes the 01: and still shows the machine that had the 01: in the past 7 days.
I have a table called devices. Each location has a unique ID number. Each device runs a job at 1am and 7pm. Devices should have 1 entry for 01:00:00 per week then 3 entries for 19:00:00 per week. Ex of cell data is 2017-10-23 19:00:02.
So I begin with
Select * From devices
Where locationid=##
AND jobdate < DATE_SUB(NOW(), INTERVAL 7 DAY))
AND jobdate not like '%01:%'
What I get in result is the machine that did run at 01:00 2 days ago. The job date shows 19:00 so it sounds like it just removed the 01:.
I am thinking of grouping the job data then say list the computer that did not have 2017-10-23 01:00:02 .

Answer 1

There is a good deal of intuition in the following suggestion, more on that later.
Most databases don't actually store date/time information is a WYSIWYG fashion. Indeed if you think about it long enough you will understand that date/times are really "sets of numbers". That is why we can do things like calculate the number of days from date1 to date2 etc. So, IF the data is stored as a datetime data type don't attempt to use LIKE (which is for text) against a datetime column. Instead look for date and time related functions that may apply to your situation. Here you are looking for not equal to specific time of day (I think). So, to remove "date" from consideration convert it to "time", and then you can filter on that.
So below, I introduce a new column jobtime which is the time portion of jobdate, and then I look for any times not equal to a given value.
SQL Fiddle
MySQL 5.6 Schema Setup:
CREATE TABLE Devices
(`locationid` varchar(2), `jobdate` datetime)
;
INSERT INTO Devices
(`locationid`, `jobdate`)
VALUES
('##', '2017-10-23 01:00:00'),
('##', '2017-10-23 19:00:02')
;
Query 1:
select
*
from (
select locationid, cast(jobdate as time) jobtime, jobdate
from devices
) d
where locationid = '##'
and jobtime <> '01:00:00'
;
Results:
| locationid | jobtime | jobdate |
|------------|----------|----------------------|
| ## | 19:00:02 | 2017-10-23T19:00:02Z |
...
why is there "intuition" above? (the "more on this later")
It is remarkably frustrating to not know which database is in use because the syntax differs so much between the vendors. It is also essential to know the EXACT data type of the jobdate column - because if it is varchar for example I have just made a complete fool of myself in the query above. In other words we are not likely to answer because key facts are missing.
Finally, you have data! It's in your table(s) already. Why not make it easy on everyone by sharing a few bits of it? Provide "sample data" with your question, and the "expected result" too (i.e. provide 2 things, not one without the other, and do not use images of data!!!). Hopefully you can see from the example above how useful sample data & result is. For example, if my intuition is way off, you can tell in an instant that it is - even if you don't read the SQL.
Rant over, not all points raised here apply to this question.