我的 SQL Server 数据库表中有一些记录需要传输到支付处理 API。仅传输 = 0 的表记录才会发送到 API。我发现this question这有助于我理解手头的错误。
我想将数据库表中的记录读取到 C# 类中，解析为 JSON，然后通过 API 调用发送。我尝试过使用 Entity Framework Core，但当我调用存储过程并将结果添加到我的模型类时，收到空引用异常，如下所示:
public async Task<IEnumerator<Onboarding>> GetOnboardingList()
{
try
{
using (var context = new SOBOContext())
{
var ob = await context.Onboarding
//.Where(o => o.Transmitted == false)
.FromSql("Execute GetUnsentOnboardingRecords_sp")
.ToListAsync();
Console.WriteLine(ob.ToArray());
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
return new OnboardingList().GetEnumerator();
}
当尝试使用 Entity Framework Core 时，我创建了 OnboardingList 类，如下所示:
public class OnboardingList : IEnumerable<Onboarding>
{
private readonly List<Onboarding> _onboarding;
public IEnumerator<Onboarding> GetEnumerator()
{
return _onboarding?.GetEnumerator();
}
IEnumerator IEnumerable.GetEnumerator()
{
return _onboarding.GetEnumerator();
}
}
然后我恢复到调用存储过程的 SqlDataReader。该方法的部分内容如下:
var listOnboardingModel = new List<Onboarding>();
try
{
using (SqlConnection connection = new SqlConnection(builder.ConnectionString))
{
SqlCommand cmd = new SqlCommand("GetUnsentOnboardingRecords_sp", connection)
{
CommandType = CommandType.StoredProcedure
};
connection.Open();
using (var reader = cmd.ExecuteReader())
{
while (reader.Read())
{
listOnboardingModel.Add(new Onboarding
{
OnboardingId = reader[1] as int? ?? 0,
UserId = reader[2] as int?,
UserName = reader[3].ToString(),
FirstName = reader[4].ToString(),
MiddleInitial = reader[5].ToString(),
Lastname = reader[6].ToString(),
DateOfBirth = reader[7].ToString(),
Ssn = reader[8].ToString(),
Email = reader[9].ToString(),
Address1Line1 = reader[10].ToString(),
Address1Line2 = reader[11].ToString(),
Address1ApartmentNumber = reader[12].ToString(),
Address1City = reader[13].ToString(),
Address1State = reader[14].ToString(),
Address1ZipCode = reader[15].ToString(),
Address1Country = reader[16].ToString(),
DayPhone = reader[17].ToString(),
EveningPhone = reader[18].ToString(),
PhonePin = reader[19].ToString(),
MerchantSourceIp = reader[20].ToString(),
ThreatMetrixPolicy = reader[21].ToString(),
SessionId = reader[22].ToString(),
BankAccount1CountryCode = reader[23].ToString(),
BankAccount1Name = reader[24].ToString(),
BankAccount1Description = reader[25].ToString(),
BankAccount1Number = reader[26].ToString(),
BankAccount1OwnershipType = reader[27].ToString(),
BankAccount1Type = reader[28].ToString(),
BankAccount1BankName = reader[29].ToString(),
BankAccount1RoutingNumber = reader[30].ToString(),
BankAccount2CountryCode = reader[31].ToString(),
BankAccount2Name = reader[32].ToString(),
BankAccount2Number = reader[33].ToString(),
BankAccount2OwnershipType = reader[34].ToString(),
BankAccount2Type = reader[35].ToString(),
BankAccount2BankName = reader[36].ToString(),
BankAccount2Description = reader[37].ToString(),
BankAccount2RoutingNumber = reader[38].ToString(),
AuthSginerFirstName = reader[39].ToString(),
AuthSignerLastName = reader[40].ToString(),
AuthSignerTitle = reader[41].ToString(),
AverageTicket = reader[42] as int? ?? 0,
BusinessLegalName = reader[43].ToString(),
BusinessApartmentNumber = reader[44].ToString(),
BusinessAddressLine1 = reader[45].ToString(),
BusinessAddressLine2 = reader[46].ToString(),
BusinessCity = reader[47].ToString(),
BusinessState = reader[48].ToString(),
BusinessZipCode = reader[49].ToString(),
BusinessCountry = reader[50].ToString(),
BusinessDescription = reader[51].ToString(),
DoingBusinessAs = reader[52].ToString(),
Ein = reader[53].ToString(),
HighestTicket = reader[54] as int? ?? 0,
MerchantCategoryCode = reader[55].ToString(),
MonthlyBankCardVolume = reader[56] as int? ?? 0,
OwnerFirstName = reader[57].ToString(),
OwnerLastName = reader[58].ToString(),
OwnerSsn = reader[59].ToString(),
OwnerDob = reader[60].ToString(),
OwnerApartmentNumber = reader[61].ToString(),
OwnerAddress = reader[62].ToString(),
OwnerAddress2 = reader[63].ToString(),
OwnerCity = reader[64].ToString(),
OwnerRegion = reader[65].ToString(),
OwnerZipCode = reader[66].ToString(),
OwnerCountry = reader[67].ToString(),
OwnerTitle = reader[68].ToString(),
OwnerPercentage = reader[69].ToString(),
BusinessUrl = reader[70].ToString(),
CreditCardNumber = reader[71].ToString(),
ExpirationDate = reader[72].ToString(),
NameOnCard = reader[73].ToString(),
PaymentMethodId = reader[74].ToString(),
PaymentBankAccountNumber = reader[75].ToString(),
PaymentBankRoutingNumber = reader[76].ToString(),
PaymentBankAccountType = reader[77].ToString(),
Transmitted = reader[78] as bool?,
TransmitDate = reader[79].ToString(),
InternationalId = reader[80].ToString(),
DriversLicenseVersion = reader[81].ToString(),
DocumentType = reader[82].ToString(),
DocumentExpDate = reader[83].ToString(),
DocumentIssuingState = reader[84].ToString(),
MedicareReferenceNumber = reader[85].ToString(),
MedicareCardColor = reader[86].ToString(),
PaymentBankAccountName = reader[87].ToString(),
PaymentBankAccountDescription = reader[88].ToString(),
PaymentBankCountryCode = reader[89].ToString(),
PaymentBankName = reader[90].ToString(),
PaymentBankOwnershipType = reader[91].ToString()
});
}
}
connection.Close();
}
Console.WriteLine(listOnboardingModel);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
return listOnboardingModel;
当我运行控制台应用程序时，我收到错误异常抛出:'System.IndexOutOfRangeException' in System.Data.SqlClient.dll
索引超出了数组的范围。
如何防止上述超出范围异常，并确保包含数据库表中的所有符合条件的记录进行传输？
最佳答案
您似乎有两个不同的问题:
- 您的
.ToString()值为空值，这会导致空引用异常。 - 序数可能超出范围，列与提供的数值不匹配导致其超出范围。
检查DBNull.Value，否则会出现要点一。
我的假设是从一开始，而索引是从零开始的。因此第一列将从零开始，而不是从一开始。
您应该查找 Dapper 或 SqlDataReader 的一些内置实用程序，以利用更简洁的代码调用来构建您的对象。 Dapper 只需执行以下操作即可压缩代码:
IEnumerable<Sample> GetSamples() => dbConnection.Query<Sample>(...);
只要列名称与属性名称匹配，它就会填充。根据提供的实体，它看起来非常简单，但请查看文档。
此外，您还应该将命令包装在 using 语句中，这样就不会有人意外地在连接 block 中间调用 command.Dispose()事故:
using(var connection = new SqlConnection(...))
using(var command = new SqlCommand(..., ...))
{
connection.Open();
...
using(var reader = command.ExecuteReader())
while(reader.Read())
{
}
}
关于c# - 如何将数据库表内容发送到API？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/56676716/