。Selectsnofromspj,==‘J1’andcolor=‘红’;或:SelectsnofromspjWherejno=‘J1’andpnoin(Selectpnofrompwherecolor=‘红’);。SelectjnoFromjWherenotexists (Select* Fromspj,s,p ====‘天津’ =‘红’);。即查找:不存在这样的零件y,供应商S1供应了y,而工程x为选用y。SelectdistinctjnoFromspjzWherenotexists (select*fromspjxwheresno=‘S1’andnotexists (select*fromspjy ==));。Selectsname,cityfroms;、颜色、重量。Selectpname,color,weightfromp;。Selectjnofromspjwheresno=‘S1’;。,,==‘J2’;。Selectdistinctpnofro
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