Support parsing Oracle DROP CONTEXT sql

[FlyingZC]

Background

Hi community,
This issue is for #26878.

ShardingSphere parser engine helps users parse a SQL to get the AST (Abstract Syntax Tree) and visit this tree to get SQLStatement (Java Object). Currently, we are planning to enhance the support for Oracle SQL parsing in ShardingSphere.

More details:
https://shardingsphere.apache.org/document/current/en/reference/sharding/parse/

Task

This issue is to support more oracle sql parse, as follows:

DROP CONTEXT empno_ctx;

DROP CONTEXT provider_ctx;
DROP USER sysadmin_pg cascade;
DROP USER apps_user;

DROP CLUSTER personnel
   INCLUDING TABLES
   CASCADE CONSTRAINTS;

DROP CLUSTER language;

DROP CONTEXT global_cust_ctx;

Process

1. First confirm that this is a correct oracle sql syntax, if not please ignore;
2. Compare SQL definitions in Oficial SQL Doc and ShardingSphere SQL Doc;
3. If there is any difference in ShardingSphere SQL Doc, please correct them by referring to the Official SQL Doc;
4. Run mvn install the current_file_module;
5. Check whether there are any exceptions. If indeed, please fix them. (Especially xxxVisitor.class);
6. Add new corresponding SQL case in SQL Cases and expected parsed result in Expected Statment XML;
7. 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

[github-actions]

There hasn't been any activity on this issue recently, and in order to prioritize active issues, it will be marked as stale.

[github-actions]

There hasn't been any activity on this issue recently, and in order to prioritize active issues, it will be marked as stale.