update eoo.eoo_data_report e set sys =( select bys from eoo.eoo_data_report t where t.data_time= convert(numeric,'201401')
and t.index_id = e.index_id and t.report_id= convert(numeric,'1') and t.company_id=e.company_id) where e.data_time = convert(numeric,'201402')

执行不成功，提示的意思貌似是不能存在 e ，只好这样来做了：

update eoo.eoo_data_report set sys =( select bys from eoo.eoo_data_report t where t.data_time= convert(numeric,'201401')
and t.index_id = eoo.eoo_data_report.index_id and t.report_id= convert(numeric,'1') and t.company_id=eoo.eoo_data_report.company_id) where eoo.eoo_data_report.data_time = convert(numeric,'201402')

另外numeric这个字段好模糊，convert(int,'201402')同样能执行（datetime是int类型的）