Question

我有两张桌子（1：N）

CREATE TABLE master (idMaster int identity (1,1) not null,
 TheName varchar( 100) null,
 constraint pk_master primary key(idMaster) clustered)

和 -

CREATE TABLE lnk (idSlave int not null,
 idMaster int not null,
 constraint pk_lnk_master_slave(idSlave) primary key clustered)

Master.idMaster和lnk.idMaster

之间的链接

我有一个SQL查询：

 select max (master.idMaster) as idMaster,
        master.theName,
        count (lnk.idSlave) as freq
  from lnk 
  inner join master ON lnk.idMaster = master.idMaster
  Group by master.theName
  order by freq desc, master.theName

我需要将此T-SQL查询转换为Linq-to-SQL语句，最好是在C＃

中

Answer 1

您无法控制Linq-to-SQL查询的确切sql输出，但这应该可以解决问题：

var results = from slave in dataContext.lnks
                  group slave by slave.idMaster
                      into slaveByMaster
                        let count = slaveByMaster.Count()
                      orderby count
                      select new
                      {
                          slaveByMaster.Key,
                          count,
                      };

您仍然需要其他查询来计算max（master.idMaster）。像这样：

            var result2 = (from master in dataContext.masters
                       select master.idMaster).Max();

翻译存储过程 - 到Linq2SQL（count，max，group，orderby）

1 个答案: