选择第n条记录select 30thselect top 1 * from table1 where col1 not in (select top 29 col1 from table1)语句中判断之后再给出新值 & 类型转换Convert的使用SELECT Id,Name,Description,Fee=CASE Fee WHEN 0 THEN '免费' ELSE CONVERT(char(4), Fee) END from T_Service_Code如果要判断是否是null,则case后面不跟列名，在when后面跟，如：UPDATE T_User_Info SET Per...