A.select*from t1 where city_name="北京"orcity_name="上海"; B.select*from t1 where city_name="北京"and city_name="上海"; C.select*from t1 where city_name in("北京","上海"); D.select*from t1 where city_name in"北京"or"上海";
A.客戶行為的數(shù)據(jù)挖掘報(bào)告 B.描述性數(shù)據(jù)分析報(bào)告 C.產(chǎn)品和行為傾向報(bào)告 D.以上都不對(duì)
A.加入固定效應(yīng)變量 B.加入工具變量 C.加入高次項(xiàng) D.加入交互項(xiàng)