select classes as 类别, meter_reading as 抄表单位, installation_site 表安装地点, max( reading_date) 抄表日期, reading as 读数 from READING_TABLE where reading_date >=TRUNC (to_date( '${抄表日期}', 'yyyy-MM' ) + 21)and reading_date <=TRUNC (to_date( '${抄表日期}', 'yyyy-MM' ) + 23) and IS_DELETE=0group by classes,meter_reading,installation_site,reading这我自己写的，发现查询错误
