9.数据逻辑关系:D(x,y,z)←-R(x,y Z)ANDS(x y,z) AND NOT T(x,y z)表达的是A、R-(S-TB、S—R—T
9.数据逻辑关系:D(x,y,z)←-R(x,y Z)ANDS(x y,z) AND NOT T(x,y z)表达的是
A、R-(S-T
B、S—R—T
发布时间:2025-07-11 17:44:34
9.数据逻辑关系:D(x,y,z)←-R(x,y Z)ANDS(x y,z) AND NOT T(x,y z)表达的是
A、R-(S-T
B、S—R—T