oracle中：
select distinct columnid from db2admin.yc_visitstat where columnid<>' ' and columnid is not null
select * from 表名 where 字段名<>' ' and 字段名 is not null
sqlserver,mysql,db2中：
select * from 表名 where 字段名 <>''
oracle中：
select distinct columnid from db2admin.yc_visitstat where columnid<>' ' and columnid is not null
select * from 表名 where 字段名<>' ' and 字段名 is not null
sqlserver,mysql,db2中：
select * from 表名 where 字段名 <>''