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:

ALTER TYPE data_typ1 
   ADD MEMBER FUNCTION qtr(der_qtr DATE) 
   RETURN CHAR CASCADE;

CREATE OR REPLACE TYPE BODY data_typ1 IS 
  MEMBER FUNCTION prod (invent NUMBER) RETURN NUMBER IS 
  BEGIN 
  RETURN (year + invent); 
  END; 
     MEMBER FUNCTION qtr(der_qtr DATE) RETURN CHAR IS 
     BEGIN 
       IF (der_qtr < TO_DATE('01-APR', 'DD-MON')) THEN 
         RETURN 'FIRST'; 
       ELSIF (der_qtr < TO_DATE('01-JUL', 'DD-MON')) THEN 
         RETURN 'SECOND'; 
       ELSIF (der_qtr < TO_DATE('01-OCT', 'DD-MON')) THEN 
         RETURN 'THIRD'; 
       ELSE 
         RETURN 'FOURTH'; 
       END IF; 
     END; 
   END;

ALTER TYPE link2 COMPILE SPECIFICATION;
         
ALTER TYPE link2 COMPILE BODY;

ALTER TYPE person_typ FINAL;

ALTER TYPE phone_list_typ
  MODIFY ELEMENT TYPE VARCHAR(64) CASCADE;

ALTER TYPE phone_list_typ_demo
  MODIFY LIMIT 10 CASCADE;

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