Question

我不得不回到一个现有项目（几乎两个月大）进行一次小改动。我现在正在左右两侧获得例外，但它处于工作状态并部署到生产并正在运行。这些错误也很奇怪：现在所有Oracle数据类型的读取都不同。行的Number（10）di列很容易作为DataRow读取并保存到POCO各自的int属性中。但是同样的代码现在失败了。

之前正在使用的原始代码：

public static async Task<(OracleConnection connection, OracleDataAdapter adapter)> GetOraclePackage()
{
    try
    {
        // To satisfy async. serves no purpose.
        await Task.FromResult(0);

        if (WebConfigurationManager.ConnectionStrings[Constants.ConnectionStringBilling] == null)
        {
            throw new ApplicationException("Oracle connection string is not found in web.config");
        }

        var oraConnection = new OracleConnection { ConnectionString = WebConfigurationManager.ConnectionStrings[Constants.ConnectionStringBilling].ConnectionString };
        var oraDataAdapter = new OracleDataAdapter { SelectCommand = new OracleCommand { CommandType = CommandType.Text, Connection = oraConnection } };

        return (oraConnection, oraDataAdapter);
    }
    catch (OracleException oraExp)
    {
        throw new RepositoryLayerException("Oracle error in repository's helper method GetOraclePackage() " + oraExp.Message, oraExp);
    }
    catch (Exception e)
    {
        throw new RepositoryLayerException("Error in repository's helper method GetOraclePackage() " + e.Message, e);
    }
}

public async Task<IList<BDO.AirportServiceWithTerminal>> GetAllServices()
{
    var objResult = new List<BDO.AirportServiceWithTerminal>();
    var oraclePackage = await Helper.GetOraclePackage();
    var ds = new DataSet();

    try
    {
        var sql = @"
                SELECT
                    s.service_code,
                    s.account_code,
                    s.service_fees,
                    s.customer_type,
                    s.period,
                    s.ser_name_e,
                    s.isvat,
                    s.vatvalue
                FROM
                    serviceinfo s
                WHERE
                        sevice_status = '1'
                    AND
                        service_fees > 1
                    AND
                        account_code IN (
                            'AB','BC','CD','DE'
                        )
                ";

        oraclePackage.connection.Open();
        oraclePackage.adapter.SelectCommand.CommandText = sql;
        oraclePackage.adapter.Fill(ds, "ServiceList");

        if (ds.Tables[0] != null)
        {
            foreach (DataRow oneService in ds.Tables[0].Rows)
            {           
                var newTerminalService = new BDO.AirportServiceWithTerminal
                {                           
                    Code = oneService.Field<int>("service_code"),                       
                    NameEnglish = oneService.Field<string>("ser_name_e").Replace(@"""", "").Trim(),
                    Fee = oneService.Field<decimal>("service_fees"),
                    IsVat = oneService.Field<string>("isvat") == "1",
                    VatValue = int.Parse(oneService.Field<string>("vatvalue"))
                };

                objResult.Add(newTerminalService);
            }                   
        }               
    }
    catch (Exception exp)
    {
        throw new RepositoryLayerException("An error occurred while retrieving all services from billing system", exp);
    }
    finally
    {
        oraclePackage.adapter.Dispose();
        if (oraclePackage.connection.State == ConnectionState.Open) oraclePackage.connection.Close();
        oraclePackage.connection.Dispose();
    }

    return objResult;
}

现在，当它试图将service_code强制转换为int时，它会失败。我试着得到service_code的类型如下：

oneService["service_code"].GetType()

我得到UnderlyingSystemType: {Name = "Int64" FullName = "System.Int64"}或UnderlyingSystemType: {Name = "Decimal" FullName = "System.Decimal"}

（写这个问题，我开始得到十进制）

通过做一些演员来解决这个问题，因为我知道数据库没有被更改，我不能接受新类型，因为有很多。同样的情况是小数现在报告为双打。

Answer 1

在一般情况下 Oracle的Number(10)不适合int（Int32），因为Number(10)的范围更广：

Type Min Value Max Value ------------------------------------ Number(10) -9999999999 .. 9999999999 Int32 -2147483648 .. 2147483647

这就是为什么，例如9876543210可以表示为Number(10)而不是int（这就是.Net将Number(10)映射到{{的原因1}}）。如果数据库中的值保证足够小（因此实际上适合 Int64），请尝试使用int：

Convert

Oracle NUMBER（10）列报告为Int64而不是Int32

1 个答案: