`information_schema.triggers.action_reference_old_row`

mysql

type: VARCHAR NOT NULL

5.7-8

type: NULL

Note:

Always OLD.

5.1-10.8

type: VARCHAR NOT NULL

Note:

Always OLD.

type: SQL_IDENTIFIER NULL

Note:

Applies to a feature not available in PostgreSQL

10-15

type: SQL_IDENTIFIER

Note:

Applies to a feature not available in PostgreSQL

9.1-9.6