第七章回顾2-1回顾2-2目标使用变量局部变量局部变量示例2-1局部变量示例2-2全局变量全局变量示例逻辑控制语句IF-ELSE示例2-1IF-ELSE示例2-2设置输出结果的格式逻辑控制语句WHILE示例2-1DECLARE@nintWHILE(1=1)--条件永远成立BEGINSELECT@n=COUNT(*)FROMstuMarksWHEREwrittenExam<60--统计不及格人数IF(@n>0)UPDATEstuMarks--每人加2分SETwrittenExam=writtenExam+2ELSEBREAK--退出循环ENDprint'加分后的成绩如下：'SELECT*FROMstuMarks逻辑控制语句CASE-END示例2-1print'ABCDE五级显示成绩如下：'SELECTstuNo,成绩=CASEWHENwrittenExam<60THEN'E'WHENwrittenExamBETWEEN60AND69THEN'D'WHENwrittenExamBETWEEN70AND79THEN'C'WHENwrittenExamBETWEEN80AND89THEN'B'ElSE'A'ENDFROMstuMarksCASE-END课堂练习CASE-END练习答案批处理语句批处理语句示例批处理语句示例课堂综合练习课堂综合练习答案总结2-1总结2-2