國家開放大學(數(shù)據(jù)庫基礎(chǔ)與應用)問答題每日一練(2019.12.27)

DECLARE @MyNO CHAR(8)
SET @MyNO="20030001"
IF (SELECT專業(yè) FROM Students WHERE 學號=@MyNO)="計算機軟件"
BEGIN
SELECT AVG(成績) AS 平均成績
FROM Score
WHERE學號=@MyNO
END
ELSE
PRINT "學號為" +@MyNO+"的學生不存在或不屬于軟件專業(yè)"
GO