在数据库中，以下sql语句执行错误的是 A select ename,sal A from emp where comm is null order by A desc; B select deptno,avg(sal) from emp group by deptno where avg(sal)>2000; C select * from emp where (job='MANAGER' or job='ANALYST') and sal >2500; D select * from emp where ename like '%\_%' escape '\'; E select count(*) from emp where 1=1;