SQL语句中，两个关系表在创建联结过程中，若不添加联结条件将会造成什么结果？

A. 第二个值

B. 最后一个值

C. 随机选择一个值

D. 第一个值

A. SELECT cust_name FROM Customers WHERE cust_state IN (＇IL＇,＇IN＇,＇MI＇ ) UNION SELECT cust_name FROM Customers WHERE cust_name = ＇Fun4All＇;

B. SELECT cust_name FROM Customers WHERE cust_state IN (＇IL＇,＇IN＇,＇MI＇ ) UNION SELECT cust_contact FROM Customers WHERE cust_name = ＇Fun4All＇;

C. SELECT * FROM Customers WHERE cust_state IN (＇IL＇,＇IN＇,＇MI＇ ) UNION SELECT * FROM Customers WHERE cust_name = ＇Fun4All＇;

D. SELECT * FROM Customers WHERE cust_state IN (＇IL＇,＇IN＇,＇MI＇ ) UNION SELECT cust_name FROM Customers WHERE cust_name = ＇Fun4All＇;

A. 随机森林

B. Adaboost

C. GBDT

D. XGBoost

A. reduce

B. join

C. left join

D. map

A. 绿色

B. 灰色

C. 红色

D. 黑色

A. 过滤

B. Union

C. Substract

D. Map