Currently, Debezium has one parser for MariaDb and Mysql, located at:

debezium-ddl-parser/src/main/antlr4/.../MySqlParser.g4

and the tests located at:

debezium-ddl-parser/src/test/resources/mysql/...

These tests run in MariaDB but no in MySql.

In the Parser code, specific sections running just in MariaDb have the comment:

//MariaDB-specific only

To give an example, these instructions work just in MariaDB but not in MySQL

• ALTER TABLE customers ADD COLUMN IF NOT EXISTS column_a INT;

• CREATE OR REPLACE TABLE `t_table`
• ... DEFINER = CURRENT_ROLE{}
• ... IDENTIFIED VIA

I suggest divide the parser in  MariadbParser.g4 and MysSqlParser.g4