数据库系统概念第六版答案(包括实践习题,习题)例如3.11答案Exercises •WritethefollowingqueriesinSQL,usingtheuniversityschema. •FindthenamesofallstudentswhohavetakenatleastoneComp.Sci.course;makesuretherearenoduplicatenamesintheresult. •FindtheIDsandnamesofallstudentswhohavenottaken