我有一个设备、地址和公司的数据集，需要导入到我们的数据库中，并发现我们的数据库可能已经包含新数据集中包含的特定设备/地址/公司。如果是这种情况，我需要使用数据集中的新信息更新该条目，不包括地址。我们检查该地址的精确副本是否存在，否则我们创建一个新条目。
我的问题是尝试在 EF 中获取设备/公司非常慢，如果存在则更新它，否则插入它。为了解决这个问题，我尝试获取所有公司、设备和地址，并将它们插入到各自的 hashmap 中，并检查新数据的标识符是否存在于 hashmap 中。这并没有导致任何性能提升。我在下面包含了我的代码。通常我会进行批量插入，但我不确定我会为批量更新做什么。有人可以建议不同的路线吗？
var context = ObjectContextHelper.CurrentObjectContext;
var oldDevices = context.Devices;
var companies = context.Companies;
var addresses = context.Addresses;
Dictionary<string, Company> companyMap = new Dictionary<string, Company>(StringComparer.OrdinalIgnoreCase);
Dictionary<string, Device> deviceMap = new Dictionary<string, Device>(StringComparer.OrdinalIgnoreCase);
Dictionary<string, Address> addressMap = new Dictionary<string, Address>(StringComparer.OrdinalIgnoreCase);
foreach (Company c in companies)
{
if (c.CompanyAccountID != null && !companyMap.ContainsKey(c.CompanyAccountID))
companyMap.Add(c.CompanyAccountID, c);
}
foreach (Device d in oldDevices)
{
if (d.SerialNumber != null && !deviceMap.ContainsKey(d.SerialNumber))
deviceMap.Add(d.SerialNumber, d);
}
foreach (Address a in addresses)
{
string identifier = GetAddressIdentifier(a);
if (!addressMap.ContainsKey(identifier))
addressMap.Add(identifier, a);
}
foreach (DeviceData.TabsDevice device in devices)
{
// update a device
Company tempCompany;
Address tempAddress;
Device currentDevice;
if (deviceMap.ContainsKey(device.SerialNumber)) //update a device
deviceMap.TryGetValue(device.SerialNumber, out currentDevice);
else // insert a new device
currentDevice = new Device();
currentDevice.SerialNumber = device.SerialNumber;
currentDevice.SerialNumberTABS = device.SerialNumberTabs;
currentDevice.Model = device.Model;
if (device.CustomerAccountID != null && device.CustomerAccountID != "")
{
companyMap.TryGetValue(device.CustomerAccountID, out tempCompany);
currentDevice.CustomerID = tempCompany.CompanyID;
currentDevice.CustomerName = tempCompany.CompanyName;
}
if (companyMap.TryGetValue(device.ServicingDealerAccountID, out tempCompany))
currentDevice.CompanyID = tempCompany.CompanyID;
currentDevice.StatusID = 1;
currentDevice.Retries = 0;
currentDevice.ControllerFamilyID = 1;
if (currentDevice.EWBFrontPanelMsgOption == null) // set the Panel option to the default if it isn't set already
currentDevice.EWBFrontPanelMsgOption = context.EWBFrontPanelMsgOptions.Where( i => i.OptionDescription.Contains("default")).Single();
// link the device to the existing address as long as it is actually an address
if (addressMap.TryGetValue(GetAddressIdentifier(device.address), out tempAddress))
{
if (GetAddressIdentifier(device.address) != "")
currentDevice.Address = tempAddress;
else
currentDevice.Address = null;
}
else // insert a new Address and link the device to it (if not null)
{
if (GetAddressIdentifier(device.address) == "")
currentDevice.Address = null;
else
{
tempAddress = new Address();
tempAddress.Address1 = device.address.Address1;
tempAddress.Address2 = device.address.Address2;
tempAddress.Address3 = device.address.Address3;
tempAddress.Address4 = device.address.Address4;
tempAddress.City = device.address.City;
tempAddress.Country = device.address.Country;
tempAddress.PostalCode = device.address.PostalCode;
tempAddress.State = device.address.State;
addresses.AddObject(tempAddress);
addressMap.Add(GetAddressIdentifier(tempAddress), tempAddress);
currentDevice.Address = tempAddress;
}
}
if (!deviceMap.ContainsKey(device.SerialNumber)) // if inserting, add to context
{
oldDevices.AddObject(currentDevice);
deviceMap.Add(device.SerialNumber, currentDevice);
}
}
context.SaveChanges();