JSON column support

[brandonkelly]

Description

Adds support for JSON columns, as Craft 4 requires MySQL 5.7.8+ which supports it.

No breaking changes are introduced here. JSON data can continue to be stored in TEXT columns if desired, and craft\db\ActiveRecord will continue normalizing arrays into JSON on set for them.

Plugin developers can choose to start storing JSON data in JSON columns by doing the following:

1. Write a migration that A) ensures all existing data is valid JSON if invalid JSON was previously allowed; and B) converts the column to JSON:

   $this->convertColumnToJson('{{%mytable}}', 'myColumn');

2. Ensure that the column’s data is never being JSON-encoded before being set on the ActiveRecord model, or when being set on an insert/update/upsert command.
3. Update the install migration to use $this->json() (e.g. instead of $this->text()).

Related discussions

• Schema::TYPE_JSON fields aren’t saved to the database as JSON #9040

[linear]

DEV-52 JSON column support

#9040