proc sql;
        select empid,jobcode,salary, /*变量用comma隔开*/
               salary*.06 as bonus   /*创建新变量*/
           from sasuser.payrollmaster
           where salary<32000
           order by jobcode;
     quit;

         proc sql;
        select empid,jobcode,salary,
               salary*.06 as bonus
           from sasuser.payrollmaster
           where salary<32000
           order by 2 desc, 1 ;  *order变量位置,根据jobcode降序，再empid升序; 
     quit;


        proc sql;
        select salcomps.empid,lastname,  /*两个表有公共列时，必须指定该列的前缀*/
               newsals.salary,newsalary
           from sasuser.salcomps,sasuser.newsals
           where salcomps.empid=newsals.empid
           order by lastname;

proc sql;
   select therapy1999.month,walkjogrun,swim,
          treadmill,newadmit,
          walkjogrun+swim as Exercise
      from sasuser.therapy1999,sasuser.totals2000
      where therapy1999.month=totals2000.month;  /*两个表，变量前一定要加数据集名字*/
quit;


proc sql;
        select membertype,
               sum(milestraveled) as TotalMiles
           from sasuser.frequentflyers
           group by membertype;   /*若没有上面的sum，功能和order一样*/
proc sql;
   select sex, avg(age) as AverageAge,
          avg(weight) as AverageWeight
      from sasuser.diabetes
      group by sex;
quit;
/*创建sas.dataset*/
 proc sql;
        create table work.miles as
           select membertype,
                  sum(milestraveled) as TotalMiles
              from sasuser.frequentflyers
              group by membertype;

    proc print data=work.miles;
    run;

       proc sql;
        select jobcode,avg(salary) as Avg
           from sasuser.payrollmaster
           group by jobcode
           having avg(salary)>40000 and  avg(salary)<50000 /*和group连用，和where功能一样*/
           order by jobcode;