set serverout on; declare n number:=1; v varchar2(20):='world'; begin dbms_output.put_line('hello'||n||v); end;

set serverout on; declare emp_count number; begin select count(*) into emp_count from emp where sal>=3000; if emp_count>0 then dbms_output.put_line('有'||emp_count||'个员工的基本薪资大于等于3000'); else dbms_output.put_line('没有员工的基本薪资大于等于3000'); end if; end;

set serverout on; declare emp_count number; begin select count(*) into emp_count from emp where sal>=3000; if emp_count=1 then dbms_output.put_line('有1个员工的基本薪资大于等于3000'); else if emp_count>1 then dbms_output.put_line('有超过1个员工的基本薪资大于等于3000'); else dbms_output.put_line('没有员工的基本薪资大于等于3000'); end if; end if; end;

set serverout on; declare emp_count number; begin select count(*) into emp_count from emp where sal>=3000; case emp_count when 0 then dbms_output.put_line('没有员工的基本薪资大于等于3000'); when 1 then dbms_output.put_line('有1个员工的基本薪资大于等于3000'); when 2 then dbms_output.put_line('有2个员工的基本薪资大于等于3000'); when 3 then dbms_output.put_line('有3个员工的基本薪资大于等于3000'); else dbms_output.put_line('超过3个员工的基本薪资大于等于3000'); end case; end;

set serverout on; declare g_id number:=2; g_losal number; g_hisal number; begin loop if(g_id>4) then exit; end if;

select losal,hisal into g_losal,g_hisal from salgrade where grade=g_id;
dbms_output.put_line(g_id || '等级的最低薪资'|| g_losal || '，最高薪资：' || g_hisal);

g_id:=g_id+1;

end loop; end;

set serverout on; declare g_id number:=2; g_losal number; g_hisal number; begin

while g_id<5 loop

 select losal,hisal into g_losal,g_hisal from salgrade where grade=g_id;
 dbms_output.put_line(g_id || '等级的最低薪资'|| g_losal || '，最高薪资：' || g_hisal);   
 g_id:=g_id+1;

end loop;

end;

set serverout on; declare g_losal number; g_hisal number; begin for g_id in 2..4 loop select losal,hisal into g_losal,g_hisal from salgrade where grade=g_id; dbms_output.put_line(g_id || '等级的最低薪资'|| g_losal || '，最高薪资：' || g_hisal);
end loop; end;