2. ROWS_AFFECTED is renamed to ROW_COUNT
(see SQL2002 specification)
3. CONNECTION_ID/TRANSACTION_ID are renamed to CURRENT_CONNECTION/CURRENT_TRANSACTION
(see SQL2002 recommendations for context functions)
4. Solved most of the shift/reduce conflicts and all reduce/reduce conflicts in the grammar
5. Fixed ambiguity in ORDER BY clause, when both the value and the clause itself could contain COLLATE word
(now explicit collation sequence of the value is used in the ordering logic)
6. Some of newly introduced tokens are made non-reserved
7. Added code to enable ORDER/GROUP BY ordinal when asterisk is used in the select list
(not sure which version it should go, so it's commented out so far)
New helper class created to serve it properly.
2. Added exception re-raise semantics.
Syntax: EXCEPTION;
If there was handled exception, re-initiate it, otherwise evaluate to no-op.
3. Implemented run-time exception messages.
Syntax: EXCEPTION <exception_name> [<value>];
If <value> is specified, evaluate it and use instead of RDB$EXCEPTION_MESSAGE.
4. Added new SQLCODE and GDSCODE system variables.
Available in procedures/triggers only.
If there wasn't any exception raised, return zero (success), otherwise return an error code.
5. Implemented ROWS_AFFECTED system variable.
Available in procedures/triggers only.
Count rows affected by the last INSERT/UPDATE/DELETE statement.
For any other statement, result is always zero.
