A.select sname,age from xsb where age>20and age<23 B.select*from xsb where age between20 and 23 C.select sname,age from xsb where agebetween20 and 23
A.主碼 B.外碼 C.域 D.映像
A.999.00,990.00 B.999.00,1000.00 C.998.00,1000.00 D.999.00,999.99