Calculating the difference between two time values by means of SQL

users
#1

Hello,

Two columns of a table (for the database engine “HyperSQL” within the application
“LibreOffice Base 7.1.0.3-985.1”) have got the data type “TIME”.
I would like to compute a difference for these fields.

It seems that the following SQL statement is insufficient so far.

SELECT ID, t1, t2, t2 - t1 AS duration FROM time_measurements1

I would appreciate your advices.

Would you like to point further information sources out besides query examples
which work with dates and time stamps?

Regards,
Markus

#2

Howdy,

The salient point here is the version of HSQLdb which comes with
LibreOffice is rather old and lacking when it comes to date
manipulation, but it can be done and hopefully this post over at ASK
dot LibreOfffice will help answer you question:
https://ask.libreoffice.org/en/question/75480/how-to-do-basic-arithmatic-with-dates-in-libre-base-queries/

best wishes,

Drew

#3

Hi,

SELECT ID, t1, t2, t2 - t1 AS duration FROM time_measurements1

You are looking for the function DATEDIFF(string, datetime1, datetime2)
Could be this works, if you have choosen a datetime field, not only a
time field.
SELECT ID, t1, t2, DATEDIFF('hour', t1, t2) AS duration FROM
time_measurements1

Would you like to point further information sources out besides query examples
which work with dates and time stamps?

You are German, right?
have a look at "Base Handbuch" and also "Base Beispiele". In "Base
Beispiele" is an example für getting times for running or something like
this.

Regards

Robert

#4

You are looking for the function DATEDIFF(string, datetime1, datetime2)

Thanks for your information.

I got distracted by the key word “DATE” while I was looking for the support of
an other time unit.
An SQL statement like the following can fit to my application needs.

SELECT "day", "start", "stop",
       DATEDIFF( 'minute', "start", "stop" ) / 60.000 AS "duration"
FROM "time_measurements";

Will any adjustments become more helpful also for the software documentation?

Regards,
Markus