c# - 向模型存储库发送查询

Question

请帮忙。我是 ASP.NET MVC 的新手，我正在尝试向存储库发送查询，但它给了我一个错误:

Errr 3 Cannot implicitly convert type 'System.Collections.Generic.List' to 'System.Collections.Generic.IList'. An explicit conversion exists (are you missing a cast?)

我正在使用一个架构类，其中只有我需要的列。这是我用于存储库的代码。

public class SSGridRepository : SSGridIRepository
{
    private DataClassesSSDataContext db;

    public SSGridRepository()
    {
        db = new DataClassesSSDataContext();
    }

    public IList<SSQuerySchema> ListAll()
    {

        var SSQuery = (from HISTORies in db.HISTORies
                       join SSes in db.SSes on HISTORies.WO equals SSes.WO
                       join SSCUSTOMs in db.SSCUSTOMs on SSes.WO equals SSCUSTOMs.WO
                       join StatusTables in db.StatusTables on new { STATUS = SSes.STATUS } equals new { STATUS = StatusTables.Status }
                       join StatusTable_1 in db.StatusTables on new { OLDSTATUS = HISTORies.OLDSTATUS } equals new { OLDSTATUS = StatusTable_1.Status }
                       join StatusTable_2 in db.StatusTables on new { NEWSTATUS = HISTORies.NEWSTATUS } equals new { NEWSTATUS = StatusTable_2.Status }
                       where
                         HISTORies.OLDSTATUS == "m" &&
                         HISTORies.NEWSTATUS == "n" &&
                         HISTORies.ACTION == "Change Job Status" &&
                         HISTORies.OLDSTATUS != HISTORies.NEWSTATUS &&
                         HISTORies.DATE.Value.Year == Convert.ToDateTime(DateTime.Now).Year ||
                         HISTORies.OLDSTATUS != HISTORies.NEWSTATUS &&
                         HISTORies.NEWSTATUS == "m" &&
                         HISTORies.ACTION == "Checked In Work Order" &&
                         HISTORies.DATE.Value.Year == Convert.ToDateTime(DateTime.Now).Year
                       orderby
                         HISTORies.DATE
                       select new
                       {
                           HISTORies.WO,
                           SSes.TITLE,
                           SSes.DESCRIPT,
                           SSCUSTOMs.CUSTNAME,
                           SSes.STAKER,
                           HISTORies.USER,
                           SSes.STATUS,
                           HISTORies.OLDSTATUS,
                           HISTORies.NEWSTATUS,
                           CURRENT_STATUS = StatusTables.Description,
                           OLD_STATUS = StatusTable_1.Description,
                           NEW_STATUS = StatusTable_2.Description,
                           HISTORies.DATE.Value.Month,
                           HISTORies.DATE
                       }).Distinct();
        return SSQuery.ToList();
    }        
}

Answer 1

在你的 Linq 中你这样做:

select new  {
                           HISTORies.WO,
                           SSes.TITLE,
                           SSes.DESCRIPT,
                           SSCUSTOMs.CUSTNAME,
                           SSes.STAKER,
                           HISTORies.USER,
                           SSes.STATUS,
                           HISTORies.OLDSTATUS,
                           HISTORies.NEWSTATUS,
                           CURRENT_STATUS = StatusTables.Description,
                           OLD_STATUS = StatusTable_1.Description,
                           NEW_STATUS = StatusTable_2.Description,
                           HISTORies.DATE.Value.Month,
                           HISTORies.DATE
                       }

这是一个动态类型，所以它不会匹配你的返回类型 List<SSQuerySchema>

尝试初始化您在 Linq 中指定的类型并设置属性。

  select new SSQuerySchema {
                               // initialize all properties here
                           }