string sqlStr = @"SELECT top 20 ID,CAST(DOI as DATETIME) as IDate
               FROM DTable";

var results = db.Database.sqlQuery<SRVM>(sqlStr);


//get total count
var total = results.Count();

我收到错误：

The specified cast from a materialized ‘System.DateTime’ type to the
‘System.String’ type is not valid.

有什么想法吗？