sub-queries
WHERE-clause operators
join inner-join
NULL-values General-Functions NV2
COUNT-Function MAX-Function FIRST-Function SUM-Function AVG-Function LAST-Function MIN-Function aggregate-functions
COUNT-Function aggregate-functions NULL-values
NULL-values constraints NOT-NULL-constraint
COALESCE General-Functions NVL NULL-values NULLIF NV2
CREATE-statement
limit-keyword TOP-clause ROWNUM
