[@loopback/sequelize] Cannot use Loopback entity “array” property type with MySQL / MariaDB datasource

[KalleV]

Describe the bug

If you try to save or update an entity with an “array” property, it will lead to a mysqld error for invalid data. This is caused by unserialized arrays being passed as parameters through the mysql2 driver.

Relates to: #9598

Logs

No response

Additional information

As a workaround, I tried changing the Loopback entity array properties to the “object” type but that causes a conflict with the Loopback request validation expecting an array type to be passed in the request.

Serializing arrays to a string for non-Postgres dialects at the Sequelize extension layer is likely the most straightforward way to resolve this.

References:

• https://sequelize.org/docs/v6/other-topics/other-data-types/#arrays-postgresql-only
• https://stackoverflow.com/questions/41860792/how-can-i-have-a-datatype-of-array-in-mysql-sequelize-instance

Reproduction

N/A