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:

EXPLAIN PLAN FOR
  SELECT XMLQuery('/PurchaseOrder/LineItems/LineItem' PASSING OBJECT_VALUE RETURNING CONTENT)
    FROM po_clob
    WHERE XMLExists('/PurchaseOrder/LineItems/LineItem
                     [ora:contains(Description, "Picnic") > 0]' PASSING OBJECT_VALUE)
      AND XMLEXists('/PurchaseOrder[User="SBELL"]' PASSING OBJECT_VALUE);

EXPLAIN PLAN FOR 
  SELECT * FROM emp_comp WHERE department_id = 20;

EXPLAIN PLAN FOR 
  SELECT * FROM emp_range 
  WHERE hire_date < TO_DATE('1-JAN-1992','DD-MON-YYYY');

EXPLAIN PLAN FOR
SELECT country, prod, year, sales
FROM sales_view
WHERE country IN ('Italy', 'Japan')
MODEL UNIQUE DIMENSION
  PARTITION BY (country) DIMENSION BY (prod, year) MEASURES (sale sales)
  RULES UPSERT
  (sales['Bounce', 2003] = AVG(sales)[ANY, 2002] * 1.24,
   sales['Y Box', 2003] = sales['Bounce', 2003] * 0.25);

EXPLAIN PLAN FOR 
  SELECT * FROM emp_range 
  WHERE hire_date >= TO_DATE('1-JAN-1996','DD-MON-YYYY');

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