queries, 46–51
concatenating strings and, 49–50
DUAL tables and, 46–48, 47
multiple vs. CUBE and ROLLUP and, 135
NULL values and, 48
numeric literals and, 50
operator precedence and, 50–51
string literals and, 49–50
queries, advanced SQL, 119–139
CUBE, 135, 136–137
ROLLUP, 134–136
set operators, 126–130, 126–134
INTERSECT, 130–132
MINUS, 132–134
UNION and UNION ALL, 126–130
subqueries, 120–126
correlated, 123–124
multiple-column, 125–126
multiple-row, 121–123
single-row, 120–121
quotas, defined, 227