How to realize the rounding operation of datetime time field in MySQL

This article is about how to implement rounding of datetime time fields in MySQL. Xiaobian thinks it is quite practical, so share it with everyone for reference. Let's follow Xiaobian and have a look.

1. Background

The maximum time of the day is obtained by Java code, and then stored in the database. The database table field format datetime retains 0 bits.

now.with(LocalTime.MAX)

A small line of code to get the maximum date of the day.

When he looked at the database, he found that the next day's time was saved.

It looks like it's rounded off!

2. Simulation test

After execution, look at the log:

2021-09-28T23:59: 59.9999999 was used, but strangely, the database stored 2021-09-29 00:00:00.

Try SQL directly:

This…was indeed rounded off.

Try MariaDB instead!

docker pull mariadbdocker run -d --name mariadb -p 33306:33306 -e "MYSQL_ROOT_PASSWORD=root" mariadbdocker exec -it mariadb bash

MariaDB discards redundant digits directly!

3. Conclusion

MySQL time is rounded if the value passed in exceeds the precision range.

MariaDB time is discarded if the value passed in exceeds the precision range.

A small dent. Finally, hard-coded!

Now.with(LocalTime.parse("23:59:59")) Thank you for reading! About "MySQL how to achieve datetime field rounding operation" This article is shared here, I hope the above content can be of some help to everyone, so that everyone can learn more knowledge, if you think the article is good, you can share it to let more people see it!