在 course 表 property 字段上添加检查约束,正确的 SQL 语句是()
A.
A alter table course add constraint ck_cno check ( property in ( ' 考试 ',' 考查 ' ))
B.
B alter table course drop constraint ck_cno
C.
C alter table course add check ( property in ( ' 考试 ',' 考查 ' ))
D.
alter table course add constraint ck_cno check property in ( ' 考试 ',' 考查 ' )