ASP.NET MVC5 add 2 Sync Times to the Application - model-view-controller

I Added the 2 Sync Times to my DB as 2 new columns and inserted values as below:
USE [DB]
ALTER TABLE [dbo].[TableName]
ADD ColumnName2 time, ColumnName3 time
This was for adding the columns.
For inserting the row values I did:
USE DB
INSERT INTO TableName (ColumnName2, ColumnName3)
VALUES ('20:30:00', '23:30:00')
This was the data for the fixed times in the rows of those columns.
I also went through all the layers of the application such as (controller, models, views, queries, services, interfaces, and so forth. NOW when I try to update any of the new times added they default to the first time that already existed on the table as a COLUMN with time in the row.
I could not post the image for the time fields from the application because it is not permitted. However, the image is in a little panel and consists of 3 fields (textboxfor) with a time picker for each one.
Any help would be greatly appreciated.
Thanks
Now I thought I would post some of the example code to see if this helps
// My controller method for those sync times
[HttpPost]
[Page(PageName.UpdateSystemConfigTime)]
public ActionResult UpdateTime(SystemMaintenanceViewModel model)
{
var dateTime = DateTime.ParseExact(model.SystemConfiguration.SynchronizationTime, "h:mm tt", CultureInfo.InvariantCulture);
var dateTime2 = DateTime.ParseExact(model.SystemConfiguration.SynchronizationTime2, "h:mm tt", CultureInfo.InvariantCulture);
var dateTime3 = DateTime.ParseExact(model.SystemConfiguration.SynchronizationTime3, "h:mm tt", CultureInfo.InvariantCulture);
//model.ProcessTime
if (model.SystemConfiguration.SynchronizationTime != null &&
model.SystemConfiguration.SynchronizationTime2 != null &&
model.SystemConfiguration.SynchronizationTime3 != null);
{
var sysConfig = new DTO.SystemSync.SystemConfiguration
{
SyncTime = dateTime.TimeOfDay,
SyncTime2 = dateTime2.TimeOfDay,
SyncTime3 = dateTime3.TimeOfDay
};
configService.UpdateSyncTime(sysConfig);
configService.UpdateSyncTime2(sysConfig);
configService.UpdateSyncTime3(sysConfig);
}
return RedirectToAction("Index");
}
////My Private method
private SystemConfiguration GetSystemConfig()
{
var model = new SystemConfiguration();
var config = configService.GetSyncTime();
configService.GetSyncTime2();
configService.GetSyncTime3();
if (config == null) return model;
var ts = config.SyncTime;
if (ts != null)
{
model.SynchronizationTime = ts.ToString();
}
var ts2 = config.SyncTime2;
if (ts2 != null)
{
model.SynchronizationTime2 = ts2.ToString();
}
var ts3 = config.SyncTime3;
if (ts3 != null)
{
model.SynchronizationTime3 = ts3.ToString();
}
return model;
============================================================================
/// My configuration command
namespace --.--.Commands
{
public class ConfigurationCommand : CommandBase, IConfigurationCommand
{
static ConfigurationCommand()
{
ConfigureAutoMapper();
}
private static void ConfigureAutoMapper()
{
Mapper.CreateMap<SystemConfiguration, entity.SystemConfiguration>()
.ForMember(dest => dest.SyncTime, opt => opt.ResolveUsing<TimeSpanToSqlTimeResolver>())
.ForMember(dest => dest.SyncTime2, opt => opt.ResolveUsing<TimeSpanToSqlTimeResolver>())
.ForMember(dest => dest.SyncTime3, opt => opt.ResolveUsing<TimeSpanToSqlTimeResolver>());
}
public void UpdateSyncTime(SystemConfiguration timeOfDay)
{
Guard.NotNull(timeOfDay);
var mapped = Mapper.Map<entity.SystemConfiguration>(timeOfDay);
var config = Context.SystemConfigurations.SingleOrDefault();
//if this is the first time, then we need to insert
if (config == null)
{
var newConfig = new entity.SystemConfiguration
{
SyncTime = mapped.SyncTime
};
Context.SystemConfigurations.Add(newConfig);
}
else
{
config.SyncTime = mapped.SyncTime;
}
SaveChanges();
}
public void UpdateSyncTime2(SystemConfiguration timeOfDay)
{
Guard.NotNull(timeOfDay);
var mapped = Mapper.Map<entity.SystemConfiguration>(timeOfDay);
var config = Context.SystemConfigurations.SingleOrDefault();
if (config == null)
{
var newConfig = new entity.SystemConfiguration
{
SyncTime2 = mapped.SyncTime2
};
Context.SystemConfigurations.Add(newConfig);
}
else
{
config.SyncTime2 = mapped.SyncTime2;
}
SaveChanges();
}
public void UpdateSyncTime3(SystemConfiguration timeOfDay)
{
Guard.NotNull(timeOfDay);
var mapped = Mapper.Map<entity.SystemConfiguration>(timeOfDay);
var config = Context.SystemConfigurations.SingleOrDefault();
if (config == null)
{
var newConfig = new entity.SystemConfiguration
{
SyncTime3 = mapped.SyncTime3
};
Context.SystemConfigurations.Add(newConfig);
}
else
{
config.SyncTime3 = mapped.SyncTime3;
}
SaveChanges();
}
}
}
=========================================================================================================
// My configuration service
namespace --.--.--.SystemSync
{
public class ConfigurationService : IConfigurationService
{
private IConfigurationQuery query;
private IConfigurationCommand command;
public ConfigurationService(IConfigurationQuery query,IConfigurationCommand command)
{
this.query = query;
this.command = command;
}
public void UpdateSyncTime(SystemConfiguration timeOfDay)
{
command.UpdateSyncTime(timeOfDay);
}
public void UpdateSyncTime2(SystemConfiguration timeOfDay)
{
command.UpdateSyncTime2(timeOfDay);
}
public void UpdateSyncTime3(SystemConfiguration timeOfDay)
{
command.UpdateSyncTime3(timeOfDay);
}
public SystemConfiguration GetSyncTime()
{
return query.GetSyncTime();
}
public SystemConfiguration GetSyncTime2()
{
return query.GetSyncTime2();
}
public SystemConfiguration GetSyncTime3()
{
return query.GetSyncTime3();
}
public List<PageResource> GetPages()
{
return query.GetPages().ToList();
}
}
}

You made a comment about fixed times, Are you looking for something like this?
CREATE TABLE [dbo].[Zamen](
[Id] [int] IDENTITY(1,1) NOT NULL,
[time1] [time](3) NOT NULL,
[time2] [time](3) NOT NULL,
[Content] [varchar](100) NULL,
CONSTRAINT [PK_Zamen] PRIMARY KEY CLUSTERED
(
[Id] ASC
))
GO
ALTER TABLE [dbo].[Zamen] ADD CONSTRAINT [DF_Zamen_time1] DEFAULT (getdate()) FOR [time1]
GO
ALTER TABLE [dbo].[Zamen] ADD CONSTRAINT [DF_Zamen_time2] DEFAULT (getdate()) FOR [time2]
GO
Those alter table statements allow the time to be automatically inserted. So when you do this:
INSERT INTO Zamen (Content) VALUES ('demo')
The current times are placed into the values.
*After seeing the code you added, some input:
In your UpdateTime Action Method, a problem that stands out is you are calling UpdateTimeSync three times, but passing it all three variables each time. I would suggest to refactor your update method -- instead of three update methods, use one update method for all time variables.

Related

ASP.NET MVC validation return lowercase property name

In my ASP.NET MVC Core web application the Json serialization of properties is set to camel case (with first letter lowercase):
services.AddMvc()
.SetCompatibilityVersion(CompatibilityVersion.Version_2_1)
.AddJsonOptions(opt =>
{
opt.SerializerSettings.ContractResolver = new DefaultContractResolver { NamingStrategy = new CamelCaseNamingStrategy() };
opt.SerializerSettings.Converters.Add(new StringEnumConverter(true));
});
The serialization to the client is working as expected.
But when the javascript client tries to post data and this data is not valid, he receives a validation message with capital letter properties, this validation messages are the ModelState:
{"Info":["The Info field is required."]}
Is there a way to make ASP.NET return lowercase property in validation messages of the ModelState to reflect the naming strategy?
The solution is to disable the automatic api validation filter and create own json result with the validation messages:
services.Configure<ApiBehaviorOptions>(options =>
{
options.SuppressModelStateInvalidFilter = true;
});
And in the controller:
protected ActionResult ValidationFailed()
{
var errorList = ModelState.ToDictionary(
kvp => kvp.Key.ToCamelCase(),
kvp => kvp.Value.Errors.Select(e => e.ErrorMessage).ToArray()
);
return BadRequest(errorList);
}
public async Task<ActionResult> Create([FromBody]TCreateDto model)
{
if (ModelState.IsValid == false)
{
return ValidationFailed();
}
...
}
The string helper method:
public static string ToCamelCase(this string name)
{
if (string.IsNullOrEmpty(name))
{
return name;
}
return name.Substring(0, 1).ToLower() + name.Substring(1);
}
There is an easier solution. Use Fluent Validator's ValidatorOptions.Global.PropertyNameResolver. Taken from here and converted to C# 8 and Fluent Validation 9:
In Startup.cs, ConfigureServices use:
services
.AddControllers()
.SetCompatibilityVersion(CompatibilityVersion.Version_3_0)
.AddFluentValidation(fv =>
{
fv.RegisterValidatorsFromAssemblyContaining<MyValidator>();
// Convert property names to camelCase as Asp.Net Core does https://github.com/FluentValidation/FluentValidation/issues/226
ValidatorOptions.Global.PropertyNameResolver = CamelCasePropertyNameResolver.ResolvePropertyName;
})
.AddNewtonsoftJson(NewtonsoftUtils.SetupNewtonsoftOptionsDefaults);
and resolver itself:
/// <summary>
/// Convert property names to camelCase as Asp.Net Core does
/// https://github.com/FluentValidation/FluentValidation/issues/226
/// </summary>
public class CamelCasePropertyNameResolver
{
public static string? ResolvePropertyName(Type type, MemberInfo memberInfo, LambdaExpression expression)
{
return ToCamelCase(DefaultPropertyNameResolver(type, memberInfo, expression));
}
private static string? DefaultPropertyNameResolver(Type type, MemberInfo memberInfo, LambdaExpression expression)
{
if (expression != null)
{
var chain = PropertyChain.FromExpression(expression);
if (chain.Count > 0)
{
return chain.ToString();
}
}
if (memberInfo != null)
{
return memberInfo.Name;
}
return null;
}
private static string? ToCamelCase(string? s)
{
if (string.IsNullOrEmpty(s) || !char.IsUpper(s[0]))
{
return s;
}
var chars = s.ToCharArray();
for (var i = 0; i < chars.Length; i++)
{
if (i == 1 && !char.IsUpper(chars[i]))
{
break;
}
var hasNext = (i + 1 < chars.Length);
if (i > 0 && hasNext && !char.IsUpper(chars[i + 1]))
{
break;
}
chars[i] = char.ToLower(chars[i], CultureInfo.InvariantCulture);
}
return new string(chars);
}
}
I have faced the same issue. I have overridden DefaultProblemDetailsFactory.cs from the source code and add logic to change the first letters in the 'errors' dictionary.
Steps:
1 - Create new CustomProblemDetailsFactory.cs class:
internal sealed class CustomProblemDetailsFactory : ProblemDetailsFactory
{
private readonly ApiBehaviorOptions _options;
public CustomProblemDetailsFactory(IOptions<ApiBehaviorOptions> options)
{
_options = options?.Value ?? throw new ArgumentNullException(nameof(options));
}
public override ProblemDetails CreateProblemDetails(
HttpContext httpContext,
int? statusCode = null,
string? title = null,
string? type = null,
string? detail = null,
string? instance = null)
{
statusCode ??= 500;
var problemDetails = new ProblemDetails
{
Status = statusCode,
Title = title,
Type = type,
Detail = detail,
Instance = instance,
};
ApplyProblemDetailsDefaults(httpContext, problemDetails, statusCode.Value);
return problemDetails;
}
public override ValidationProblemDetails CreateValidationProblemDetails(
HttpContext httpContext,
ModelStateDictionary modelStateDictionary,
int? statusCode = null,
string? title = null,
string? type = null,
string? detail = null,
string? instance = null)
{
if (modelStateDictionary == null)
{
throw new ArgumentNullException(nameof(modelStateDictionary));
}
statusCode ??= 400;
var problemDetails = new ValidationProblemDetails(modelStateDictionary)
{
Status = statusCode,
Type = type,
Detail = detail,
Instance = instance,
};
if (title != null)
{
// For validation problem details, don't overwrite the default title with null.
problemDetails.Title = title;
}
// FIX LOWERCASE, MAKE THE FIRST LETTERS LOWERCASE
///-----------------------------
if (problemDetails.Errors != null)
{
var newErrors = problemDetails.Errors.ToDictionary(x => this.MakeFirstLetterLowercase(x.Key), x => x.Value);
problemDetails.Errors.Clear();
foreach (var keyValue in newErrors)
{
problemDetails.Errors.Add(keyValue.Key, keyValue.Value);
}
}
///-----------------------------
ApplyProblemDetailsDefaults(httpContext, problemDetails, statusCode.Value);
return problemDetails;
}
private void ApplyProblemDetailsDefaults(HttpContext httpContext, ProblemDetails problemDetails, int statusCode)
{
problemDetails.Status ??= statusCode;
if (_options.ClientErrorMapping.TryGetValue(statusCode, out var clientErrorData))
{
problemDetails.Title ??= clientErrorData.Title;
problemDetails.Type ??= clientErrorData.Link;
}
var traceId = Activity.Current?.Id ?? httpContext?.TraceIdentifier;
if (traceId != null)
{
problemDetails.Extensions["traceId"] = traceId;
}
}
private string MakeFirstLetterLowercase(string str)
{
if (!string.IsNullOrEmpty(str) && char.IsUpper(str[0]))
{
return str.Length == 1 ? char.ToLower(str[0]).ToString() : char.ToLower(str[0]) + str[1..];
}
return str;
}
}
2 - In the Startup.cs override the default ProblemDetailsFactory:
services.AddSingleton<ProblemDetailsFactory, CustomProblemDetailsFactory>();
After that all keys in the dictionary 'errors' will start with lowercase

Trying to save comma-separated list

Trying to save selections from a CheckBoxList as a comma-separated list (string) in DB (one or more choices selected). I am using a proxy in order to save as a string because otherwise I'd have to create separate tables in the DB for a relation - the work is not worth it for this simple scenario and I was hoping that I could just convert it to a string and avoid that.
The CheckBoxList uses an enum for it's choices:
public enum Selection
{
Selection1,
Selection2,
Selection3
}
Not to be convoluted, but I use [Display(Name="Choice 1")] and an extension class to display something friendly on the UI. Not sure if I can save that string instead of just the enum, although I think if I save as enum it's not a big deal for me to "display" the friendly string on UI on some confirmation page.
This is the "Record" class that saves a string in the DB:
public virtual string MyCheckBox { get; set; }
This is the "Proxy", which is some sample I found but not directly dealing with enum, and which uses IEnumerable<string> (or should it be IEnumerable<Selection>?):
public IEnumerable<string> MyCheckBox
{
get
{
if (String.IsNullOrWhiteSpace(Record.MyCheckBox)) return new string[] { };
return Record
.MyCheckBox
.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries)
.Select(r => r.Trim())
.Where(r => !String.IsNullOrEmpty(r));
}
set
{
Record.MyCheckBox = value == null ? null : String.Join(",", value);
}
}
To save in the DB, I am trying to do this in a create class:
proxy.MyCheckBox = record.MyCheckBox; //getting error here
but am getting the error:
Cannot implicitly convert 'string' to System.Collections.Generic.IEnumerable'
I don't know, if it's possible or better, to use Parse or ToString from the API for enum values.
I know that doing something like this will store whatever I put in the ("") into the DB, so it's just a matter of figuring out how to overcome the error (or, if there is an alternative):
proxy.MyCheckBox = new[] {"foo", "bar"};
I am not good with this stuff and have just been digging and digging to come up with a solution. Any help is much appreciated.
You can accomplish this using a custom user type. The example below uses an ISet<string> on the class and stores the values as a delimited string.
[Serializable]
public class CommaDelimitedSet : IUserType
{
const string delimiter = ",";
#region IUserType Members
public new bool Equals(object x, object y)
{
if (ReferenceEquals(x, y))
{
return true;
}
var xSet = x as ISet<string>;
var ySet = y as ISet<string>;
if (xSet == null || ySet == null)
{
return false;
}
// compare set contents
return xSet.Except(ySet).Count() == 0 && ySet.Except(xSet).Count() == 0;
}
public int GetHashCode(object x)
{
return x.GetHashCode();
}
public object NullSafeGet(IDataReader rs, string[] names, object owner)
{
var outValue = NHibernateUtil.String.NullSafeGet(rs, names[0]) as string;
if (string.IsNullOrEmpty(outValue))
{
return new HashSet<string>();
}
else
{
var splitArray = outValue.Split(new[] {Delimiter}, StringSplitOptions.RemoveEmptyEntries);
return new HashSet<string>(splitArray);
}
}
public void NullSafeSet(IDbCommand cmd, object value, int index)
{
var inValue = value as ISet<string>;
object setValue = inValue == null ? null : string.Join(Delimiter, inValue);
NHibernateUtil.String.NullSafeSet(cmd, setValue, index);
}
public object DeepCopy(object value)
{
// return new ISet so that Equals can work
// see http://www.mail-archive.com/nhusers#googlegroups.com/msg11054.html
var set = value as ISet<string>;
if (set == null)
{
return null;
}
return new HashSet<string>(set);
}
public object Replace(object original, object target, object owner)
{
return original;
}
public object Assemble(object cached, object owner)
{
return DeepCopy(cached);
}
public object Disassemble(object value)
{
return DeepCopy(value);
}
public SqlType[] SqlTypes
{
get { return new[] {new SqlType(DbType.String)}; }
}
public Type ReturnedType
{
get { return typeof(ISet<string>); }
}
public bool IsMutable
{
get { return false; }
}
#endregion
}
Usage in mapping file:
Map(x => x.CheckboxValues.CustomType<CommaDelimitedSet>();

EmitMapper and List

It's the first time that I use EmitMapper.
I have a list of object ex: Customer and I would like to map this list in a ienumerable of CustomerDTO how can I do that?
Tnx
It's straightforward if you have a list and want to convert it to list of DTOs:
var mapper = ObjectMapperManager.DefaultInstance.GetMapper<Customer, CustomerDTO>();
IEnumerable<CustomerDTO> dtos = listOfCustomer.Select(mapper.map);
The preblem is when the list is in another object, for example User and UserDTO:
class User {
public List<Customer> Customers { get; set; }
}
class UserDTO {
public IEnumerable<CustomerDTO> Customers { get; set; }
}
It seems that EmitMapper does not support conversion from List to Enumerable. A way to support it would be:
var customerMapper = ObjectMapperManager
.DefaultInstance.GetMapper<Customer, CustomerDTO>();
var mapper = ObjectMapperManager.DefaultInstance
.GetMapper<User, UserDTO>(
new DefaultMapConfig()
.ConvertUsing<List<Customer>, IEnumerable<CustomerDTO>>(
a => a.Select(customerMapper.Map))
);
This can be done creating a custom class, implementing the interface "ICustomConverterProvider" and adding a ConvertGeneric to the "DefaultMapConfig".
Looking on the source code of EmitMapper, i found a class named "ArraysConverterProvider", which is the default generic converter from ICollections to Arrays.
Adapting the code from this class to work with IEnumerable collections:
class GenericIEnumerableConverterProvider : ICustomConverterProvider
{
public CustomConverterDescriptor GetCustomConverterDescr(
Type from,
Type to,
MapConfigBaseImpl mappingConfig)
{
var tFromTypeArgs = DefaultCustomConverterProvider.GetGenericArguments(from);
var tToTypeArgs = DefaultCustomConverterProvider.GetGenericArguments(to);
if (tFromTypeArgs == null || tToTypeArgs == null || tFromTypeArgs.Length != 1 || tToTypeArgs.Length != 1)
{
return null;
}
var tFrom = tFromTypeArgs[0];
var tTo = tToTypeArgs[0];
if (tFrom == tTo && (tFrom.IsValueType || mappingConfig.GetRootMappingOperation(tFrom, tTo).ShallowCopy))
{
return new CustomConverterDescriptor
{
ConversionMethodName = "Convert",
ConverterImplementation = typeof(GenericIEnumerableConverter_OneTypes<>),
ConverterClassTypeArguments = new[] { tFrom }
};
}
return new CustomConverterDescriptor
{
ConversionMethodName = "Convert",
ConverterImplementation = typeof(GenericIEnumerableConverter_DifferentTypes<,>),
ConverterClassTypeArguments = new[] { tFrom, tTo }
};
}
}
class GenericIEnumerableConverter_DifferentTypes<TFrom, TTo> : ICustomConverter
{
private Func<TFrom, TTo> _converter;
public IEnumerable<TTo> Convert(IEnumerable<TFrom> from, object state)
{
if (from == null)
{
return null;
}
TTo[] result = new TTo[from.Count()];
int idx = 0;
foreach (var f in from)
{
result[idx++] = _converter(f);
}
return result;
}
public void Initialize(Type from, Type to, MapConfigBaseImpl mappingConfig)
{
var staticConverters = mappingConfig.GetStaticConvertersManager() ?? StaticConvertersManager.DefaultInstance;
var staticConverterMethod = staticConverters.GetStaticConverter(typeof(TFrom), typeof(TTo));
if (staticConverterMethod != null)
{
_converter = (Func<TFrom, TTo>)Delegate.CreateDelegate(
typeof(Func<TFrom, TTo>),
null,
staticConverterMethod
);
}
else
{
_subMapper = ObjectMapperManager.DefaultInstance.GetMapperImpl(typeof(TFrom), typeof(TTo), mappingConfig);
_converter = ConverterBySubmapper;
}
}
ObjectsMapperBaseImpl _subMapper;
private TTo ConverterBySubmapper(TFrom from)
{
return (TTo)_subMapper.Map(from);
}
}
class GenericIEnumerableConverter_OneTypes<T>
{
public IEnumerable<T> Convert(IEnumerable<T> from, object state)
{
if (from == null)
{
return null;
}
return from;
}
}
This code is just a copy with a minimum of adaptation as possible and can be applyed to objects with many levels of hierarchy.
You can use the above code with the following command:
new DefaultMapConfig().ConvertGeneric(
typeof(IEnumerable<>),
typeof(IEnumerable<>),
new GenericIEnumerableConverterProvider());
This saved my day and I hope to save yours too! hehehe

Compare 2 lists using linq

I'm a linq noob.... can someone please some me how to achieve this using linq... I'm trying to compare 2 lists in both directions...
internal void UpdateUserTeams(int iUserID)
{
UserTeamCollection CurrentTeams = GetUserTeams(iUserID);
UserTeamCollection UpdatedTeams = this;
foreach (UserTeam ut in CurrentTeams)
{
if(!UpdatedTeams.ContainsTeam(ut.ID))
{
RemoveTeamFromDB();
}
}
foreach (UserTeam ut in UpdatedTeams)
{
if (!CurrentTeams.ContainsTeam(ut.ID))
{
AddTeamToDB();
}
}
}
public bool ContainsTeam(int iTeamID)
{
return this.Any(t => t.ID == iTeamID);
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Linqage
{
class Program
{
static void Main(string[] args)
{
UserTeamCollection currentTeams = new UserTeamCollection()
{
new UserTeam(1),
new UserTeam(2),
new UserTeam(3),
new UserTeam(4),
new UserTeam(5)
};
UserTeamCollection updatedTeams = new UserTeamCollection()
{
new UserTeam(2),
new UserTeam(4),
new UserTeam(6),
new UserTeam(8)
};
currentTeams.Except(updatedTeams).All(u =>
{
//Console.WriteLine("Item ID: {0}",u.ID);
//RemoveFromDB()
return true;
});
updatedTeams.Except(currentTeams).All(u =>
{
//Console.WriteLine("Item ID: {0}", u.ID);
//AddToDB()
return true;
});
}
}
public class UserTeamCollection
: List<UserTeam>
{
}
//Either overwrite the GetHashCode and Equals method OR create a IComparer
public class UserTeam
{
public int ID { get; set; }
public UserTeam(int id)
{
ID = id;
}
public override bool Equals(object obj)
{
UserTeam iOther = obj as UserTeam;
if (iOther != null)
{
return this.ID == iOther.ID;
}
return false;
}
public override int GetHashCode()
{
return ID.GetHashCode();
}
}
}
So converting your initial question to an english requirement:
foreach (UserTeam ut in CurrentTeams) // for each current team
{
if(!UpdatedTeams.ContainsTeam(ut.ID)) // that is not in the updated teams list
{
RemoveTeamFromDB(); // remove it from the database
}
}
foreach (UserTeam ut in UpdatedTeams) //for each of the teams in the updated teams list
{
if (!CurrentTeams.ContainsTeam(ut.ID)) //if the current team does not contain the updated team
{
AddTeamToDB(); //add the team to the database
}
}
Therefore, you want to do:
//select all current teams that are not in updated teams list
CurrentTeam.Except(UpdatedTeams).All(team => { RemoveTeamFromDB(team); return true; });
//select all updated teams that are not in the current teams list
UpdatedTeam.Except(CurrentTeams).All(team => { AddTeamToDB(team); return true; });
Make sure your UserTeam object has proper overrides for the Equals and GetHashCode methods, so that comparison between two UserTeams is accurate :)
You would normally use Enumerable.Except both ways to get the differences. Then add and remove as needed.
var addedTeams = UpdatedTeams.Except(CurrentTeams);
var removedTeams = CurrentTeams.Except(UpdatedTeams);
You're trying to get the outer parts from a full outer join. Here's a rough way to achieve that.
ILookup<int, UserTeam> currentLookup = CurrentTeams
.ToLookup(ut => ut.ID);
ILookup<int, UserTeam> updatedLookup = UpdatedTeams
.ToLookup(ut => ut.ID);
List<int> teamIds = CurrentTeams.Select(ut => ut.ID)
.Concat(UpdatedTeams.Select(ut => ut.ID))
.Distinct()
.ToList();
ILookup<string, UserTeam> results =
(
from id in teamIds
let inCurrent = currentLookup[id].Any()
let inUpdated = updatedLookup[id].Any()
let key = inCurrent && inUpdated ? "No Change" :
inCurrent ? "Remove" :
inUpdated ? "Add" :
"Inconceivable"
let teams = key == "Remove" ? currentLookup[id] :
updatedLookup[id]
from team in teams
select new {Key = key, Team = team)
).ToLookup(x => x.Key, x => x.Team);
foreach(UserTeam ut in results["Remove"])
{
RemoveTeamFromDB();
}
foreach(UserTeam ut in results["Add"])
{
AddTeamToDB();
}

Help with linq2sql generic lambda expression

In my Database almost every table has its own translations table. I.e. Sports has SportsTranslations table with columns: SportId, LanguageId, Name. At the moment I'm taking translations like:
int[] defaultLanguages = { 1, 3 };
var query = from s in dc.Sports
select new
{
sportName = s.SportsTranslations.Where(st => defaultLanguages.Contains(st.LanguageID)).First()
};
I wonder is it possible to implement some kind of generic method, so I could refactor code like here:
var query = from s in dc.Sports
select new
{
sportName = s.SportsTranslations.Translate()
};
Solved. Here is the static method I written:
public static class Extras
{
public static T Translate<T>(this IEnumerable<T> table) where T : class
{
try
{
return table.Where(
t => defaultLanguages.Contains(
(int)t.GetType().GetProperty("LanguageID").GetValue(t, null)
)
).First();
}
catch (Exception)
{
throw new ApplicationException(string.Format("No translation found in table {0}", typeof(T).Name));
}
}
}

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