1，Group by 根据某个字段排序

       select Department,count(*) FROM [PPMG].[dbo].[UnConViolation] group by Department

结果如下：

2，Group by与所传参数联合使用

USE PPMGSET ANSI_NULLS ONGOSET QUOTED_IDENTIFIER ONGOAlter PROCEDURE UnConViolationTimes     @type nvarchar(50)ASBEGIN    declare @sql nvarchar(1000)    if @type is not null    begin      set @sql='select '+ @type+' as Name,count(*) as Count FROM [PPMG].[dbo].[UnConViolation] group by '+@type      print @sql      exec(@sql)    end    ENDGO

exec UnConViolationTimes 'Department'

结果如下

 

3，Group by 后台用法

public List
     
       GetUnConViolationTimes(string type)        {            var UnConViolationList = UnConViolationRepository.Query();            var ttList = UnConViolationList.GroupBy(m => new { m.Department}).Select(m => new ViolationTimesDto()            {                Name=m.Key.Department,                Count=m.Count()            }).ToList();                        return ttList;        }
     

 结果如下