sql="select discount_value from shop_discount where discount_begin_value="&sumvalue 会影响数据库吗?我运行后它是能连接但是不能连接数据库

请问sql=select * from 招聘信息 order by id sql=select * from x where Min>2 and max SQL >select count(*) from Teacher where teacherCode=? and teacherPassword=? java.sql.SQLException:SQL >select count(*) from Teacher where teacherCode=? and teacherPassword=?java.sql.SQLException: Can not issue executeUpdate() for SELECTsat com.mysql. $sql=SELECT count(*) as pcount FROM news 和$sql = UPDATE article SET这句是什么意思? String sql = select * from tb_consumer where account=' + account+ '; + account+ sql语句 后面的(+) select * from t1,t2 where t1.a=t2.b(+) $sql = select tb_note.*,answ.* from tb_note left join;这句话解释下,left 还有.*,answ.* SQL> CREATE TABLE Y AS SELECT * FROM X WHERE no=2 if (pastart = -1) sql.append(select * from(); sql.append(select nid,sname,sdescription,nprice,sif (pastart = -1)sql.append(select * from();sql.append(select nid,sname,sdescription,nprice,simg,(CASE smctag WHEN '0' THEN '有货'WHEN '1' THEN ' SQL 语句 SELECT * FROM {{table}} WHERE `fleet_end_time` Delphi 查询 Access 错误:Field 平均 not foundadoquery1.SQL.Clear;adoquery1.Close;adoquery1.sql.add('select avg(English) as 平均 from Subject');adoquery1.ExecSQL;edit1.Text := adoquery1.Fieldbyname('平均').AsStringadoquery1.sql.add('select MA 这句SQL语句是什么意思.ql=select distinct(selabel) from.sql=select distinct(selabel) from kcwl_labprosellog where isdel=0 &sqlfile& and selabel not in (select distinct(selabel) from kcwl_labprosell) 这个语句是什么作用的.说具 select id,name from student where id in ( select id from score having count(id)>=2 );以上这段语句有没语法错误.SQL语句 大侠这个查询语句的意思是什么?sql=select DISTINCT 日期 from +tablename+ where 日期>=' +df +' and 日期 sql 语句中 select * from table where 2=1 的where2=1有什么意思和作用 sql = select pro_out.*,pro.name from pro_out left join pro on pro_out.pro_id=pro.id sql=select top 1 * from news order by tim desc 中的top 1是什么作用?如题 求单表查询的hql语句怎么写sqL如下：select * from aaa20 where aaae2001 = '11111111';求hql语句写法