Insert works because we are removing the setting NO_ZERO_DATE.
If we comment (or remove) the line:
dsn.Params["sql_mode"] = strings.Replace(dsn.Params["sql_mode"], "NO_ZERO_DATE,", "", -1)The insert fails as expected
2023/03/08 17:15:55 impossible insert teacher: Error 1292 (22007): Incorrect datetime value: '0000-00-00' for column 'datetime' at row 1