SELECT-clause
sub-queries
CREATE-statement DESC-command
NULL-values General-Functions NV2
NULL-values constraints NOT-NULL-constraint
AVG-Function aggregate-functions LAST-Function SUM-Function FIRST-Function COUNT-Function MIN-Function MAX-Function
isolation phantom-read transactions REPEATABLE-READ SERIALIZABLE
Oracle SQL-server DROP-statement MS-Access DB2 MySQL DROP-INDEX
CASE-Function
ROWNUM Oracle