MySQL Database Configuration

This section documents the supported MySQL configuration.

Database Schema

The engine's MySQL database schema does not support milliseconds precision for the column types TIMESTAMP and DATETIME: I.e., a to be stored value is rounded to the next or previous second, e.g., 2021-01-01 15:00:46.731 is rounded to 2021-01-01 15:00:47.

Heads Up!

The missing millisecond’s precision for date/time values impacts the process engine's behavior. Please read how to configure the MySQL JDBC Driver to ensure that date/time values are handled correctly.

JDBC Driver Configuration

Here you can find the MySQL JDBC Driver’s configuration prerequisites to ensure a frictionless behavior of the process engine.

Disable sending milliseconds for date/time values

Heads Up!

This configuration flag is mandatory to avoid unexpected behavior when operating the process engine with MySQL.

When sending a date/time value as part of any SQL statement to the database, the MySQL JDBC Driver $\geq$ 5.1.23 sends milliseconds. This behavior is problematic since the engine's MySQL database schema does not support milliseconds precision for date/time values.

To ensure correct behavior of the process engine when sending date/time values, make sure to update your MySQL JDBC Driver to a version $\geq$ 5.1.37. You can avoid sending milliseconds to the MySQL Server in these versions by setting sendFractionalSeconds=false in your JDBC connection URL.

Please find below examples of unwanted behavior that occurs, in case the flag sendFractionalSeconds=false is not provided:

• When a user performs a task query with due date == 2021-01-01 15:00:46.731, the query returns results equal to 2021-01-01 15:00:46.731. However, since the engine's database schema does not store milliseconds, no result is returned.
• When a user sets a due date to a task, the value is rounded to the next or previous second, e.g., 2021-01-01 15:00:46.731 is rounded to 2021-01-01 15:00:47. Please also see the official MySQL documentation.