5求至少用了S供应商所供应的全部零件的工程号JNO; SQL) XP≡_(3x(1P)) SELECT DISTINCT JNO FROM SPJ SPJZ WHERE NOT EXISTS SELECT X FROM SPJ SPJX WHERE SNO=SI AND NOT EXIST C SELECT FROM SPJ SPJY WHERE SPX PNO=SPJYPNO AND SPJYJNO-SPJZJNO5 求至少用了S1供应商所供应的全部零件的工程号JNO ; ■ SQL SELECT DISTINCT JNO FROM SPJ SPJZ WHERE NOT EXISTS (SELECT * FROM SPJ SPJX WHERE SNO=‘S1’ AND NOT EXISTS ( SELECT * FROM SPJ SPJY WHERE SPJX.PNO=SPJY.PNO AND SPJY.JNO=SPJZ.JNO ) ) ∀xP ≡ ┓(ヨx(┓P ) )