select ename from emp where ename like'%A___'; 这条SQL语句中'%A___'是什么意思?

select ename from emp where ename like'%A___'; 这条SQL语句中'%A___'是什么意思? 用下列输出回答问题（使用的 E M P表）：E N A M E- - - - - - - - - -S M I T H - d o g –A L L E N - d o g –下列哪个S Q L语句产生以上输出?A.select trim(trailing '-dog' from ename) as ename from emp;B.select rpad(ename,10,' 查询语句中,共有三个部门：10,20,30,查询哪些雇员的工资高于所在部门的平均工资,请问三个命令的区别正确语句如下： SELECT deptno,ename,sal FROM emp outer WHERE sal>( SELECT avg(sal) ORACLE语句 求 create or replace procedure findName(name emp.ename%type,en out number) as i number; begin select count(*) into i from emp where ename=name; if i=1 then en:=i; dbms_output.put_line('用户存在'); else en:=0; dbms_output.put_line(' select * from book limit , 为什么数据库中的where语句不能写在order by前面select top 3 E.ename姓名,E.emp_sal工资,S.GRADE等级,D.dept_name部门名字from empEjoin deptDon E.deptno = D.deptnojoin SALSon E.emp_sal>=LOSAL and E.emp oracle变量表类型declaretype my_emp is table of scott.emp%rowtypeindex by binary_integer;new_emp my_emp;v_num number:=0;cursor cur_emp is select empno,ename,job,sal from scott.emp;--1.cursor 是个什么东东?beginfor v_emp in cur_emp loop --2.v select * from a union select * from b 能详细说下么 select from 表 和select from [表]有什么不同? select count(*) from 怎么使用 select count(1) from emp select * into dept2 from dept 1' union select * from [ADM] union select * 请问 select top 1 1 from ... // IF EXISTS (SELECT name FROM m select * into b from a where 11 SQL 语句 SELECT * FROM {{table}} WHERE `fleet_end_time` SELECT