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CHAPTER 9
NULL 1 2 3 NULL 2 3 4 NULL 1 2 4 NULL 1
Aggregation and GROUP BY
ENGL ENGL ENGL ENGL MATH MATH MATH MATH POLY POLY POLY POLY UNKN UNKN
1 3 2 4 2 3 1 1 2 3 2 1 1 1
(24 row(s) affected) The sequence of the columns in a GROUP BY clause has the eямАect of ordering the output. If we change the order of the GROUP BY, like this: SELECT class, major, COUNT(*) AS [count] FROM Student GROUP BY major, class Our result will look like this: class -----NULL NULL NULL NULL NULL NULL 1 1 1 1 2 2 2 2 2 3
major ----NULL COSC ENGL MATH POLY UNKN COSC ENGL POLY UNKN ACCT COSC ENGL MATH POLY ART
count ----------3 1 1 2 2 1 4 3 3 1 1 2 2 3 2 1