SELECT CAST(title AS char(20)) AS title, type, price, advance FROM titles WHERE ytd_sales IS NOT NULL ORDER BY type DESC COMPUTE AVG(price), SUM(advance) BY type COMPUTE SUM(price), SUM(advance) 6.2.3 鏁版嵁鎺у埗璇 █(DCL) 鏁版嵁鎺у埗璇 █(DCL)鏄 敤鏉ヨ 缃 垨鑰呮洿鏀规...
ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)FROM scLEFT JOIN sc AS T1ON sc.S# = T1.S# AND T1.C# = 'k1'LEFT JOIN sc AS T2ON sc.S# = T2.S# AND T2.C# = 'k2'LEFT JOIN sc AS T3...