FlyingZC opened a new issue, #27025: URL: https://github.com/apache/shardingsphere/issues/27025
# 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: ```sql CREATE FUNCTION Power_GreaterThanSpecific_Func( object PowerDemand_Typ, cell NUMBER, value NUMBER) RETURN NUMBER AS BEGIN IF cell <= object.CellDemandValues.LAST THEN IF (object.CellDemandValues(cell) > value) THEN RETURN 1; ELSE RETURN 0; END IF; ELSE RETURN NULL; END IF; END; ``` ```sql CREATE FUNCTION set_id RETURN NUMBER IS BEGIN IF SYS_CONTEXT ('hr', 'id') = 5 THEN RETURN 1; ELSE RETURN 2; END IF; END; ``` ```sql CREATE GLOBAL TEMPORARY TABLE today_sales ON COMMIT PRESERVE ROWS AS SELECT * FROM orders WHERE order_date = SYSDATE; ``` ```sql CREATE FUNCTION Power_LessThanAny_Func( object PowerDemand_Typ, value NUMBER) RETURN NUMBER AS idx NUMBER; BEGIN FOR idx IN object.CellDemandValues.FIRST..object.CellDemandValues.LAST LOOP IF (object.CellDemandValues(idx) < value) THEN RETURN 1; END IF; END LOOP; RETURN 0; END; ``` ```sql CREATE FUNCTION get_selectivity(relop VARCHAR2, value NUMBER, lo NUMBER, hi NUMBER, ndv NUMBER) RETURN NUMBER AS sel NUMBER := NULL; ndv NUMBER; BEGIN -- This function computes the selectivity (as a percentage) -- of a predicate -- col <relop> <value> -- where <relop> is one of: =, !=, <, <=, >, >= -- <value> is one of: 0, 1 -- lo and hi are the minimum and maximum values of the column in -- the table. This function performs a simplistic estimation of the -- selectivity by assuming that the range of distinct values of -- the column is distributed uniformly in the range lo..hi and that -- each distinct value occurs nrows/(hi-lo+1) times (where nrows is -- the number of rows). IF ndv IS NULL OR ndv <= 0 THEN RETURN 0; END IF; -- col != <value> IF relop = '!=' THEN IF value between lo and hi THEN sel := 1 - 1/ndv; ELSE sel := 1; END IF; -- col = <value> ELSIF relop = '=' THEN IF value between lo and hi THEN sel := 1/ndv; ELSE sel := 0; END IF; -- col >= <value> ELSIF relop = '>=' THEN IF lo = hi THEN IF value <= lo THEN sel := 1; ELSE sel := 0; END IF; ELSIF value between lo and hi THEN sel := (hi-value)/(hi-lo) + 1/ndv; ELSIF value < lo THEN sel := 1; ELSE sel := 0; END IF; -- col < <value> ELSIF relop = '<' THEN IF lo = hi THEN IF value > lo THEN sel := 1; ELSE sel := 0; END IF; ELSIF value between lo and hi THEN sel := (value-lo)/(hi-lo); ELSIF value < lo THEN sel := 0; ELSE sel := 1; END IF; -- col <= <value> ELSIF relop = '<=' THEN IF lo = hi THEN IF value >= lo THEN sel := 1; ELSE sel := 0; END IF; ELSIF value between lo and hi THEN sel := (value-lo)/(hi-lo) + 1/ndv; ELSIF value < lo THEN sel := 0; ELSE sel := 1; END IF; -- col > <value> ELSIF relop = '>' THEN IF lo = hi THEN IF value < lo THEN sel := 1; ELSE sel := 0; END IF; ELSIF value between lo and hi THEN sel := (hi-value)/(hi-lo); ELSIF value < lo THEN sel := 1; ELSE sel := 0; END IF; END IF; RETURN least(100, ceil(100*sel)); END; ``` # 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 -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
