support parse ALTER ROLE

[tuichenchuxin]

Hi community,

This issue is for #20305. ref to #6480

Background

ShardingSphere parser engine helps users parse a SQL to get the AST (Abstract Syntax Tree) and visit this tree to get SQLStatement (Java Object). At present, this parser engine can handle SQLs for MySQL, PostgreSQL, SQLServer, openGauss and Oracle, which means we have to understand different database dialect SQLs. More details: https://shardingsphere.apache.org/document/current/en/reference/sharding/parse/

Task

This issue is to support more sql parse.

• [ ] ALTER ROLE doc

Process

1. Compare SQL definitions in Oficial SQL Doc and ShardingSphere SQL Doc.
2. If there is any difference in ShardingSphere SQL Doc, please correct them by referring to the Official SQL Doc.
3. Run mvn install the current_file_module.
4. Check whether there are any exceptions. If indeed, please fix them. (Especially xxxVisitor.class).
5. Add new corresponding SQL case in SQL Cases and expected parsed result in Expected Statment XML.
6. Run SQLParserParameterizedTest to make sure no exceptions.

Relevant Skills

1. Master JAVA language
2. Have a basic understanding of Antlr g4 file
3. Be familiar with Oracle SQLs