Question

我的c＃中有点生疏，我之前从未使用过Oracle。我正在连接到一个具有数字（可为空）列的数据库。当我将它导入我的数据模型时，c＃将其视为double？但是，尝试查询db会抛出强制转换错误。

请参阅以下演员的各种尝试

    public decimal? REGION_ID { get; set; }
    public decimal? REGION_ORDER { get; set; }
    public decimal? DURATION { get; set; }

    Entities ctx = new Entities();
    List<Hearing> a = (from x in ctx.HEARING_LIST
                           select new Hearing()
                           {
                               REGION_ID = x.REGION_ID,
                               REGION_ORDER = x.REGION_ORDER,                                   
                               DURATION = x.DURATION
                           }).ToList();
     return a;

引发＆＃39;：指定的演员表无效。＆＃39;

所以我试过

    public decimal? REGION_ID { get; set; }
    public decimal? REGION_ORDER { get; set; }
    public string DURATION { get; set; }

    Entities ctx = new Entities();
    List<Hearing> a = (from x in ctx.HEARING_LIST
                           select new Hearing()
                           {
                               REGION_ID = x.REGION_ID,
                               REGION_ORDER = x.REGION_ORDER,                                   
                               DURATION = x.DURATION.ToString()
                           }).ToList();
     return a;

投掷预期NCHAR获得了NCLOB＆＃39;

最后

    public string DURATION { get; set; }
    Entities ctx = new Entities();
    List<Hearing> a = (from x in ctx.HEARING_LIST
                           select new Hearing()
                           {
                               REGION_ID = x.REGION_ID,
                               REGION_ORDER = x.REGION_ORDER,                                   
                               DURATION = SqlFunctions.StringConvert((double?)x.DURATION)
                           }).ToList();
     return a;

指出了＆＃39;指定的方法＆＃39; System.String StringConvert（System.Nullable`1 [System.Double]）＆＃39;在类型＆＃39; System.Data.Entity.SqlServer.SqlFunctions＆＃39;无法转换为LINQ to Entities商店表达式。＆＃39;

任何建议都将不胜感激

使用linq将Oracle Number列转换为任何c＃数据类型

0 个答案: