题目内容

以下各题使用如下3个数据库表：职员.dbf：职员号C(3)，姓名C(6)，性别C(2)，组号N(1)，职务C(10) 客户.dbf：客户号C(4)，客户名C(36)，地址C(36)，所在城市C(36) 订单.dbf：订单号C(4)，客户名C(4)，职员号C(3)，签订日期D，金额N(6.2) 有如下SQL语句： SELECT订单号，签订日期，金额 FROM 订单，职员； WHERE 订单.职员号=职员.职员号 AND 姓名="李二" 与如上语句功能相同的SQL语句是( )。

A. SELECT 订单号，签订日期，金额 FROM 订单 WHERE EXISTS；(SELECTFROM 职员 WHERE 姓名="李二")
B. SELECT订单号，签订日期，金额 FROM 订单 WHERE EXISTS；(SELECTFROM 职员 WHERE职员号=订单.职员号 AND 姓名="李二")
C. SELECT 订单号，签订日期，金额 FROM 订单 WHERE IN；(SELECT 职员号 FROM 职员 WHERE 姓名="李二")
D. SELECT 订单号，签订日期，金额 FROM 订单 WHERE IN；(SELECT 职员号 FROM 职员 WHERE 职员号=订单.职员号 AND 姓名="李二")

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