FROM P; (3) 找出使用供应商S1所供应零件的工程号码。 SELECT JNO FROM SPJ WHERE SNO=‘S1’; (4) 找出工程项目J2使用的各种零件的名称及其数量。 SELECT P.PNAME, SPJ.QTY FROM P, SPJ WHERE P.PNO=SPJ.PNO AND SPJ.JNO='J2'; (5) 找出上海厂商供应的所有零件号码。 SELECT DISTINCT PNO FROM SPJ WHERE SNO IN （SELECT SNO FROM S WHERE CITY='上海'）; (6) 找出使用上海产的零件的工程名称。 SELECT JNAME FROM J, SPJ, S WHERE J. JNO=SPJ. JNO AND SPJ. SNO=S.SNO AND S.CITY='上海'; 或 SELECT JNAME FROM J WHERE JNO IN (SELECT JNO FROM SPJ, S WHERE SPJ. SNO=S.SNO AND S.CITY='上海'); (7) 找出没有使用天津产的零件的工程号码。 SELECT JNO FROM J WHERE NOT EXISTS (SELECT * FROM SPJ WHERE SPJ.JNO=J.JNO AND SNO IN (SELECT SNO FROM S WHERE CITY=‘天津’))； 或 SELECT JNO FROM J