Failed to parse Mysql CHARACTER SET with COLLATE clause

When using SQLParser, the following ALTER TABLE statement fails to parse:
ALTER TABLE `test`.`test` MODIFY COLUMN `v` varchar(255) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL AFTER `id`,DROP PRIMARY KEY,ADD PRIMARY KEY (`id`, `v`) USING BTREE
The issue seems to be related to the presence of the COLLATE latin1_swedish_ci clause. If the COLLATE clause is removed, the statement parses successfully.

首先使用 SQLParser 重现报告的 ALTER TABLE 语句，并将其与省略 COLLATE 子句的版本进行比较。当包含 CHARACTER SET 和 COLLATE 的完整 MySQL 语句能够成功解析时，工作即完成。

由索引模型根据 Issue 内容生成。