解释C#里的数据库语句

[qq_37798348]

public List<CJGXModel> GetCJGXList(int pageIndex, int pageSize, CJGXModel model)
{
StringBuilder selectCommand = new StringBuilder();
selectCommand.AppendFormat(@" select * from(select row_number() over (order by a.ID) as rowNum,a.* from ( select top({0}) [ID],[StuId],[LessonId],[Grade],[StuName],[LessonName],[Class],[ProfessionName] FROM [PMSDB].[dbo].[CJGX]{1} ) as a) c where c.rowNum>{2}", pageSize * pageIndex, SetWhereCondition(model), pageSize * (pageIndex - 1));
SqlDataReader reader = SqlHelper.ExcuteSql(selectCommand.ToString());
return GetList(reader);
}

[-一个大坑]

我一般看不懂就调试，然后到数据库执行着看

[打老虎zz]

就是一个分页查询 先是查询前当前页之前所有数据 然后用row_number() over ()根据ID正序排序之后的数据数据做一个排序 然后取当前页的数据

[娃都会打酱油了]

就是执行一条sql语句啊 {0},{1}这类是占位符，对应后面的pageSize * pageIndex之类参数

[正怒月神]

select * from(select row_number() over (order by a.ID) as rowNum,a.* from ( select top({0}) [ID],[StuId],[LessonId],[Grade],[StuName],[LessonName],[Class],[ProfessionName] FROM [PMSDB].[dbo].[CJGX]{1} ) as a) c where c.rowNum>{2} 先看内部这句

( select top({0}) [ID],[StuId],[LessonId],[Grade],[StuName],[LessonName],[Class],[ProfessionName] FROM [PMSDB].[dbo].[CJGX]{1} ) as a

很简单说明去某个表里查询前几条（top）字段，取了别名 叫做 a 然后

(select row_number() over (order by a.ID) as rowNum,a.* from ( select top({0}) [ID],[StuId],[LessonId],[Grade],[StuName],[LessonName],[Class],[ProfessionName] FROM [PMSDB].[dbo].[CJGX]{1} ) as a) c

由于已经区别名了。那么简化先来就是

(select row_number() over (order by a.ID) as rowNum,a.* from  a) c

这里就只是给了一个rowNum标识列。并且取了别名 叫做c 最后

select * from(select row_number() over (order by a.ID) as rowNum,a.* from ( select top({0}) [ID],[StuId],[LessonId],[Grade],[StuName],[LessonName],[Class],[ProfessionName] FROM [PMSDB].[dbo].[CJGX]{1} ) as a) c where c.rowNum>{2}

整个句子就是从前面的c表中，通过rowNum来分页，然后通过传入的下标和每页行数，找到分页的内容

[qq_37798348]

C#代码里SQL语句有点复杂，看不懂，请各位帮忙解释一下