单项选择题
对于第7题的两个基本表，有一个SQL语句： SELECT ENO, ENAME FROM EMP WHERE DNO NOT IN (SELECT DNO FROM DEPT WHERE DNAME='金工车间');其等价的关系代数表达式是：______。
A．πENO,ENAME(σDNAME≠'金工车间' (EMP
DEP)
B．πENO,ENAME
C．πENO,ENAME(EM-πENO,ENAME (σDNAME='金工车间'(EMP
DEP)
D．πENO,ENAME (EM-πENO,ENAME (σDNAME≠'金工车间'(EMP
DEP)
DEP)B．πENO,ENAME
C．πENO,ENAME(EM-πENO,ENAME (σDNAME='金工车间'(EMP
DEP)D．πENO,ENAME (EM-πENO,ENAME (σDNAME≠'金工车间'(EMP
DEP)