A. SELECT S#,SNAME FROM S WHERE SNAME='刘%.' B. SELECT S#,SNAME FROM S WHERE SNAME='刘_' C. SELECT S#,SNAME FROM S WHERE SNAME LIKE'刘%.' D. SELECT S#,SNAME FROM S WHERE SNAME LIKE'刘_'
A. Ⅰ和Ⅱ B. Ⅱ和Ⅳ C. Ⅲ和Ⅳ D. Ⅰ和Ⅳ
A. S.S#=SC.S#ANDSEX='女'ANDCNAME='计算机' B. S.S#=S C.S#AND C.C#=.S C.C#ANDCNAME='计算机' C. SEX='女'and CNAME='计算机' D. 乙S#=S C.S#AND C.C#=S C.C#ANDSEX='女'AND CNAME='计算机'
A. Ⅰ、Ⅱ B. Ⅱ、Ⅲ C. Ⅲ、Ⅳ D. Ⅰ、Ⅲ
A. SELECT s.sname FROM s, sc WHEREC.cno='C1' B. SELECT s.sname FROM s, sc WHERE C.cno='C1'AND s.sno=sC.sno C. SELECT s.sname FROM s, sc WHERE D. cno='C1'AND s.sno=s
A. SELECT sno FROM sc WHERE grade=NULL B. SELECT sno FROM sc WHERE grade IS C. SELECT sno FROM sc WHERE grade IS NULL D. SELECT sno FROM sc WHERE grade=0
A. Ⅰ和Ⅱ B. Ⅰ和Ⅲ C. Ⅱ和Ⅲ D. Ⅰ、Ⅱ和Ⅲ
A. 只有Ⅰ B. 只有Ⅱ C. Ⅰ和Ⅱ D. 都不可以
A. 只有Ⅰ B. 只有Ⅱ C. 都能 D. 都不能
A. SELECT S#,SNAME FROM S WHERE SNAME =′刘%′ B. SELECT S#,SNAME FROM S WHERE SNAME =′刘_′ C. SELECT S#,SNAME FROM S WHERE SNAME LIKE′刘%′ D. SELECT S#,SNAME FROM S WHERE SNAME LIKE′刘_′