已知PROJECT(J#,JNAME,DATE),要求若没有视图或约束引用属性DATE,则删除该列,若有视图或约束引用该属性,则不删除该列。可实现上述语义的语句是______。
A.DELETE TABLE PROJECT DROP DATE CASCADE
B.DELETE TABLE PROJECT DROP DATE RESTRICT
C.ALTER TABLE PROJECT DROP DATE CASCADE
D.ALTER TABLE PROJECT DROP DATE RESTRICT