我正在尝试从dot和api获取加密价格，并使用dotnet core 3.1（预览版）和ef core 3将其保存到数据库中。获取数据没有问题，但是'context.SaveChanges（）'抛出一个'算术溢出错误'异常：

'Arithmetic overflow error converting numeric to data type numeric.
The statement has been terminated.'

我已经尝试在模型中增加小数精度和小数位数，但是我仍然做错了什么，无法弄清它是什么。

型号：

    public class PoloniexTradingPair
    {

        // this is the poloniex ID!
        public int Id { get; set; }
        [Key]
        public int PoloniexTradingPairId { get; set; }

        [Column(TypeName = "decimal(30,28)")]
        public Decimal last { get; set; }

        [Column(TypeName = "decimal(30,28)")]
        public Decimal lowestAsk { get; set; }

        [Column(TypeName = "decimal(30,28)")]
        public Decimal highestBid { get; set; }

        [Column(TypeName = "decimal(30,28)")]
        public Decimal percentChange { get; set; }

        [Column(TypeName = "decimal(30,28)")]
        public Decimal baseVolume { get; set; }

        [Column(TypeName = "decimal(38,20)")]
        public Decimal quoteVolume { get; set; }

        public int isFrozen { get; set; }

        [Column(TypeName = "decimal(30,28)")]
        public Decimal high24hr { get; set; }

        [Column(TypeName = "decimal(30,28)")]
        public Decimal low24hr { get; set; }


    }

结果数据库表：

CREATE TABLE [dbo].[PoloniexTradingPairs](
    [PoloniexTradingPairId] [int] IDENTITY(1,1) NOT NULL,[Id] [int] NOT NULL,[last] [decimal](30,28) NOT NULL,[lowestAsk] [decimal](30,[highestBid] [decimal](30,[percentChange] [decimal](30,[baseVolume] [decimal](30,[quoteVolume] [decimal](38,20) NOT NULL,[isFrozen] [int] NOT NULL,[high24hr] [decimal](30,[low24hr] [decimal](30,CONSTRAINT [PK_PoloniexTradingPairs] PRIMARY KEY CLUSTERED 
(
    [PoloniexTradingPairId] ASC
)WITH (PAD_INDEX = OFF,STATISTICS_NORECOMPUTE = OFF,IGNORE_DUP_KEY = OFF,ALLOW_ROW_LOCKS = ON,ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO

方法：

void getPoloniexTradingPairs()
{
    using (ApplicationDbContext context = new ApplicationDbContext())
    {


        using (var httpClient = new HttpClient())
        {


            var rates = httpClient.GetStringAsync("https://poloniex.com/public?command=returnTicker");
            JObject rates_json = JObject.Parse(rates.Result);
            // Log.Information(rates_json.ToString());

            foreach (var tradingpair in rates_json)
            {
                Log.Information(tradingpair.Key);
                PoloniexTradingPair pair = JsonConvert.DeserializeObject<PoloniexTradingPair>(tradingpair.Value.ToString());
                Log.Information("logging pair");
                Log.Information(JsonConvert.SerializeObject(pair).ToString());
                context.Add(pair);

                Log.Information(pair.highestBid.ToString());

            }

            context.SaveChanges();



            /*
                JObject rates_json2 = JObject.Parse(rates_json.First.First.Last.First.ToString());
                string rates_json3 = rates_json.First.First.First.Last.ToString();
                CB_ExchangeRates ExchangeRates = JsonConvert.DeserializeObject<CB_ExchangeRates>(rates_json.First.First.Last.First.ToString());
                ExchangeRates.currency = rates_json3;

                context.Add(ExchangeRates);
                context.SaveChanges();
                Log.Information(JsonConvert.SerializeObject(ExchangeRates));
                Log.Information("success!");
            */


            /*
            Log.Information("Pulling coinbase for exchange rates...");
            var json = httpClient.GetStringAsync("https://api.coinbase.com/v2/prices/BTC-EUR/buy");

            JObject jobject = JObject.Parse(json.Result);


            CB_BTCEUR btceur = new CB_BTCEUR { Basecurrency = (string)jobject["data"]["base"],Targetcurrency = (string)jobject["data"]["currency"],Amount = (string)jobject["data"]["amount"] };
            */


        }
    }
}

运行时期间，配对看起来像预期的那样：

    Id  7   int
    PoloniexTradingPairId   0   int
    baseVolume  0.70627038  decimal
    high24hr    0.00000005  decimal
    highestBid  0.00000004  decimal
    isFrozen    0   int
    last    0.00000004  decimal
    low24hr 0.00000004  decimal
    lowestAsk   0.00000005  decimal
    percentChange   0.00000000  decimal
    quoteVolume 17019678.54214583   decimal

我不知道如何找出哪个值真正导致了问题，并且除了“行号3”外，找不到任何异常信息。我假设它是指SQL查询，有什么方法可以查看查询吗？ 该数据库似乎反映了我的模型，但是还是有问题。

感谢您提供解决此问题的任何提示！ ：）