I a am new to entity framework. I have created project with Entity Model. When i am trying to add item in to the table it gives error "Multiplicity Constraint violated" Any idea?
ID From Table MAPPER is FK in MAPS table.
In Code Behind:
private Mapper mMapper;
if (mMapper.Id == 0)
db.Mappers.Add(mMapper);
db.SaveChanges();
public partial class Mapper
{
public Mapper()
{
this.Maps = new HashSet<Map>();
}
public int Id { get; set; }
public string Name { get; set; }
public string RecordDelimiter { get; set; }
public string ValueDelimiter { get; set; }
public Nullable<int> ColumnDescriptionRow { get; set; }
public Nullable<int> FirstRowOfData { get; set; }
public Nullable<bool> IgnoreThisRecord { get; set; }
public Nullable<bool> ExplodePartQuantity { get; set; }
public Nullable<bool> IgnoreImportingErrors { get; set; }
public Nullable<int> AngleMappingLeadingEdgeId { get; set; }
public Nullable<int> AngleMappingTrailingEdgeId { get; set; }
public string ValueWrapper { get; set; }
public string ValueWrapperDelimiter { get; set; }
public virtual AngleMapping AngleMapping { get; set; }
public virtual AngleMapping AngleMapping1 { get; set; }
public virtual ICollection<Map> Maps { get; set; }
}
Help Appreciated!
Related
I work on an API and when I want to get data from a many-to-many relationship, I get back null.
The connection with the database is OK, and Post date work.
But when I get info from the database, the table for the many-to-many relationship is empty
public class User
{
[Key]
public int Id { get; set; }
[Required]
[MaxLength(30)]
public string Pseudo { get; set; }
[EmailAddress]
public string Mail { get; set; }
[Required]
public string Pwd { get; set; }
[Required]
public bool IsAdmin { get; set; }
public ICollection<Project> UsersProjectstry { get; set; }
public ICollection<UserProjectMTM> UsersProjects { get; set; }
}
public class Project
{
[Key]
public int Id { get; set; }
[Required]
[MaxLength(30)]
public string Name { get; set; }
[Required]
[MinLength(100)]
public string Description { get; set; }
public string? img { get; set; }
[Required]
public DateTime StartDate { get; set; }
[Required]
public DateTime EndDate { get; set; }
[Required]
public int SumGoal { get; set; }
public int Sum { get; set; }
[Required]
public User ProjectManager { get; set; }
public ICollection<UserProjectMTM> Donator { get; set; }
}
public class UserProjectMTM
{
public int PId { get; set; }
public Project Project { get; set; }
public int UId { get; set; }
public User User { get; set; }
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.ApplyConfiguration(new ProjectConfig());
modelBuilder.ApplyConfiguration(new UserConfig());
modelBuilder.ApplyConfiguration(new CommentConfig());
modelBuilder.Entity<UserProjectMTM>().HasKey(x => new { x.UId, x.PId });
modelBuilder.Entity<UserProjectMTM>().HasOne(p=> p.Project).WithMany(u=> u.Donator).HasForeignKey(x=>x.PId);
modelBuilder.Entity<UserProjectMTM>().HasOne(u => u.User).WithMany(p=> p.UsersProjects).HasForeignKey(x => x.UId);
}
public IEnumerable<TEntity> GetAll()
{
return _Context.Set<TEntity>();
}
public TEntity? GetById(params object[] Id)
{
return _Context.Set<TEntity>().Find(Id);
}
I try a lot of things - so far without success.
I'm junior and I can't find the solution - please help.
I am trying to insert value in DateTime column with Entity Framework but it throwing error on db.SaveChanges() function. There are 2 DateTime columns but exception throwing for only one (entry.OT_Date) with no maximum detail.
var entry = new OT_Request_N();
entry.Emp_ID = StaticFunctions.WindowUserId;
entry.slno = db.OT_Request_N.Max(x=>x.slno)+1;
entry.OT_Date= otD;
entry.OT_Time_Req = hourRequest;
entry.Remarks_Req = sError.ReqRemarks;
entry.Req_Sent_On = DateTime.Now;
entry.Supervisor_ID = sError.ManagerID;
entry.Approve_Status = 0;
db.OT_Request_N.Add(entry);
db.SaveChanges();
Here is SQL table Design
Here is class generated in edmx file
public partial class OT_Request_N
{
public int slno { get; set; }
public string Emp_ID { get; set; }
public Nullable<System.DateTime> Req_Sent_On { get; set; }
public Nullable<int> OT_Time_Req { get; set; }
public string Supervisor_ID { get; set; }
public string Remarks_Req { get; set; }
public string Remarks_App { get; set; }
public Nullable<int> OT_Time_App { get; set; }
public string Approved_By { get; set; }
public Nullable<int> Approve_Status { get; set; }
public Nullable<System.DateTime> Approved_On { get; set; }
public Nullable<int> Operations { get; set; }
public string AltReq_ID { get; set; }
public Nullable<bool> Is_alert_sent { get; set; }
public Nullable<System.DateTime> OT_Date { get; set; }
}
I was making an API for saving a model where it has one to many relationship with another model. When I applying automapping in it. it is giving me following error:
CreateContestDto -> Contest
tritronAPI.DTOs.CreateContestDto -> tritronAPI.Model.Contest
Type Map configuration:
CreateContestDto -> Contest
tritronAPI.DTOs.CreateContestDto -> tritronAPI.Model.Contest
Destination Member:
Problems
---> AutoMapper.AutoMapperMappingException: Missing type map
configuration or unsupported mapping.
Mapping types:
ProblemDto -> Problem
tritronAPI.DTOs.ProblemDto -> tritronAPI.Model.Problem
at lambda_method(Closure , ProblemDto , Problem , ResolutionContext )
My models are: Contest and Problem a contest contain many problems:
public class Contest
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
public string Name { get; set; }
public DateTime StartTime { get; set; }
public DateTime EndTime { get; set; }
public ICollection<Problem> Problems { get; set; }
public ICollection<ContestProgrammingLanguage>
ContestProgrammingLanguages { get; set; }
}
public class Problem
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
[Required]
[MaxLength(255)]
public string ProblemName { get; set; }
[ForeignKey("User")]
public string ProblemAuthorId { get; set; }
public virtual User ProblemAuthor { get; set; }
public string AuthorName { get; set; }
//public virtual List<Resources> Resourceses { get; set; }
public string ProblemDescription { get; set; }
public bool IsPublished { get; set; }
public virtual ICollection<Submission> Submissions { get; set; }
public string Tags { get; set; }
//public Guid Contest_Id { get; set; }
public virtual Contest Contest { get; set; }
[ForeignKey("Contest")]
public int? Contest_Id { get; set; }
public short Score { get; set; }
//Timelimit in miliseconds
public int TimeLimit { get; set; }
//MemoryLimit in bytes
public int MemoryLimit { get; set; }
//More than source code limit is not allowed
public int? SourceCodeLimit { get; set; }
public virtual ICollection<TestFile> TestFiles { get; set; } = new
List<TestFile>();
}
public class CreateContestDto
{
public CreateContestDto()
{
this.Problems = new HashSet<ProblemDto>();
}
public string Name { get; set; }
public DateTime StartDate { get; set; }
public DateTime StartTime { get; set; }
public DateTime EndDate { get; set; }
public DateTime EndTime { get; set; }
public string BackgroundImage { get; set; }
public string Description { get; set; }
public ICollection<ProblemDto> Problems { get; set; }
}
public class ProblemDto
{
public int Id { get; set; }
public string ProblemName { get; set; }
}
mapping profile:
CreateMap<CreateContestDto, Contest>().ForMember(
dest => dest.Problems , opt => opt.MapFrom(src =>
src.Problems));
controller code:
public async Task<IActionResult> AddContest([FromBody]
CreateContestDto contest)
{
var con = _mapper.Map<Contest>(contest);
this._uow.ContestRepository.Add(con);
return Ok();
}
I have already tried with reversemap selecting new id in mapping profile
You also need to add mappings for ProblemDTO to Problem:
CreateMap<CreateContestDto, Contest>();
CreateMap<ProblemDto, Problem>();
This is my error :
Unable to determine the principal end of an association between the types 'SANTEK.Web.Models.SantekOrder' and 'SANTEK.Web.Models.OrderMoneySum'. The principal end of this association must be explicitly configured using either the relationship fluent API or data annotations.
What is my mistake logically ?? I mean to build one-to-one relation.
My model classes are here :
[Table("Orders")]
public class SantekOrder
{
[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int SantekOrderId { get; set; }
[Required, StringLength(25)]
[DisplayName("Çatdırılacaq şəxs")]
public string DelivaryManName { get; set; }
[DisplayName("Çatdırılacaq şəxs istifadəçidir?")]
public bool DeliveryManIsUser { get; set; }
[Required, StringLength(25)]
[DisplayName("Çatdırılacaq şəxs ad və soyadı")]
public string DelivaryManSurname { get; set; }
[Required, StringLength(10)]
[DisplayName("Çatdırılacaq şəxs tefon nömrəsi")]
public string DelivaryManTel { get; set; }
[DisplayName("Çatdırılacaq ünvan istifadəçinin ünvandır?")]
public bool IsUserAddress { get; set; }
[Required, StringLength(150)]
[DisplayName("Çatdırılacaq şəxsin ünvanı?")]
public string DelivaryManAddress { get; set; }
public int SanTekUserId { get; set; }
public int OrderMoneySumId { get; set; }
[DisplayFormat(DataFormatString = "{0:dd-MM-yyyy-hh-mm-ss}",
ApplyFormatInEditMode = true)]
public DateTime Time { get; set; }
[ForeignKey("SanTekUserId")]
public virtual SanTekUser SanUser { get; set; }
[ForeignKey("SanTekUserId")]
public virtual OrderMoneySum OrderMoneySum { get; set; }
}
This is my OrdersDetail Table to hold all product and their quantity
[Table("OrderedProducts")]
public class OrderMoneySum
{
[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int OrderMoneySumId { get; set; }
[Required]
public int SantekOrderId { get; set; }
[Required]
public int AllProductId { get; set; }
[DisplayName("Miqdarı")]
public int Quantity { get; set; }
[ForeignKey("SantekOrderId")]
public virtual SantekOrder SantekOrder { get; set; }
[ForeignKey("SantekOrderId")]
public virtual AllProduct AllProduct { get; set; }
}
I'm still new in creating Models using Entity Framework and MVC 4 Razor. I'm having a problem on how can I save a history of a model. How can I create a model that have a history on specific tables or fields ? For ex: If I wish to create a history on the changes on the school. Its still not clear to me how will I I create the model that saves history. How will be the triggering do I have to execute the save function on different models with the same data ?
Thank you so much in advance.
If anyone could be a simple example of model and a model history and how it is functioning, I'll be very grateful. Like a Sales or sales history.
Here's my code
One To Many
public class Child
{
[Key]
public int ChildID { get; set; }
[Required,Display(Name="Project Code")]
public string ProjectCode { get; set; }
public string Status { get; set; }
[DataType(DataType.Date)]
public DateTime StatusDate { get; set; }
public string FamilyName { get; set; }
public string GivenName { get; set; }
public string MiddleName { get; set; }
[DataType(DataType.Date)]
public DateTime Birthdate { get; set; }
public string Gender {get;set;}
public string Address { get; set; }
public string Section { get; set; }
public int SchoolLevelID { get; set; }
public int SchoolYearID { get; set; }
public int AreaID { get; set; }
public int SchoolID { get; set; }
public int GradeLevelID { get; set; }
//Foreign Key - One to Many
public virtual SchoolLevel SchoolLevel { get; set; }
public virtual SchoolYear SchoolYear { get; set; }
public virtual Area Area { get; set; }
public virtual School School { get; set; }
public virtual GradeLevel GradeLevel{get;set;}
//Child is foreign key at the table
public virtual ICollection<Guardian> Guardians { get; set; }
}
public class SchoolLevel
{
public int SchoolLevelID { get; set; }
public string SchoolLevelName { get; set; }
public virtual ICollection<Child> Children { get; set; }
}
public class SchoolYear
{
public int SchoolYearID { get; set; }
public string SchoolYearName { get; set; }
public virtual ICollection<Child> Children{get;set;}
}
public class Area
{
public int AreaID{get;set;}
public string AreaName { get; set; }
public virtual ICollection<Child> Children{get;set;}
}
public class School
{
public int SchoolID { get; set; }
public string SchoolName{get;set;}
public virtual ICollection<Child> Children { get; set; }
}
public class GradeLevel
{
public int GradeLevelID{get;set;}
public string GradeLevelName { get; set; }
public virtual ICollection<Child> Children { get; set; }
}
public class ChildDbContext : DbContext
{
public DbSet<Child> Children { get; set; }
public DbSet<SchoolLevel> SchoolLevels { get; set; }
public DbSet<SchoolYear> SchoolYears { get; set; }
public DbSet<Area> Areas { get; set; }
public DbSet<School> Schools { get; set; }
public DbSet<GradeLevel> GradeLevels { get; set; }
public DbSet<Guardian> Guardians { get; set; }
}
You can use this approach: Create a History model. That contains 1 changeness like o log.
public class History
{
public int HistoryId { get; set; }
public int ModelType { get; set; } //it is ModelTypeEnum value.
public int ModelId { get; set; }
public string PropertyName { get; set; }
public string Propertyvalue {get;set;}
public DateTime ChangeDate { get; set; }
public int ChangedUserId { get; set; }
}
And Enum:
public enum ModelTypeEnum
{
Child =1,
SchoolLevel = 2,
//etc..
};
For example, when you edit 1 Child entity, give changed properties name and value, it's id, type and others (ChangeDate, ChangedUserId) to History and save histories. If 3 properties will change you should save 3 history entities. Then, you can load (filter) histories by ModelId, by ChangedUserId etc.