/*    人员：LDH    功能：SQL-简单查询    日期：2018-7-18 */USE TSQLFundamentals2008;GO-- Select some columns' information.SELECT empid,    lastname,    firstname,    address,    city,    countryFROM HR.Employees;-- GROUP BYSELECT '国家' = country,    COUNT(1) AS '员工个数'FROM HR.EmployeesGROUP BY country;-- ExpressionSELECT '订单日期' = orderdate,    YEAR(orderdate) AS '订单年份'FROM Sales.Orders;