清空表数据：truncate Table tablename 查重 查找表中多余的重复记录，重复记录时根据单个字段来判断： SELECT * FROM RADA_CHN_DOR_L2_QC_F_TAB WHERE V_FILE_NAME IN (SELECT V_FILE_NAME FROM RADA_CHN_DOR_L2_QC_F_TAB GROUP BY V_FILE_NAME HAVING COUNT(V_FILE_NAME)>1) 删除表中多余的重复
