Error when make relationship between two tables one to many

Problem

The relationship from 'SalesFooter.SaleHeaders' to 'SalesHeader.SalesFooters' with foreign key properties {'SalesOrderNo' : int} cannot target the primary key {'SalesOrderNo' : int, 'SalesType' : int, 'SalesYear' : int, 'BranchCode' : int} because it is not compatible. Configure a principal key or a set of compatible foreign key properties for this relationship.

Details

I work in visual studio 2017 asp.net EntityFramework core 2.1 when i make relationship between two models SalesHeader and SalesFooter

I get error in relations why and how to solve

SalesHeader Keys : SalesOrderNo , SalesYear ,BranchCode, SalesType(composit keys)

SalesFooter Keys :SalesOrderNo , SalesYear ,BranchCode, SalesType,,SalesLineNo (composit keys)

SampleData
SalesHeader Table
SalesOrderNo SalesYear BranchCode SalesType CustomerID
50 2018 1 1 20
SalesFooter Table
SalesOrderNo SalesLineNo SalesYear BranchCode SalesType ItemCode
50 1 2018 1 1 1001
50 2 2018 1 1 1002
50 3 2018 1 1 1003

public class SalesHeader
{
public int SalesOrderNo { get; set; }
public int SalesYear { get; set; }
public int BranchCode { get; set; }
public int SalesType { get; set; }
[Required]
[DataType(DataType.Date)]
[DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
public DateTime SalesDate { get; set; }
public ICollection SalesFooters { get; set; }
[DataType("decimal(18 ,2")]
public decimal TotalPrice { get; set; }
}
public class SalesFooter
{
public int SalesOrderNo { get; set; }
public int SalesYear { get; set; }
public int BranchCode { get; set; }
public int SalesType { get; set; }
public int SalesLineNo { get; set; }
[Required]
[DataType(DataType.Date)]
[DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
public DateTime SalesDate { get; set; }
[DataType("decimal(18 ,2")]
public decimal Quantity { get; set; }
[DataType("decimal(18 ,2")]
public decimal UnitPrice { get; set; }
[DataType("decimal(18 ,2")]
public decimal Total { get; set; }
[StringLength(100)]
public string Notes { get; set; }
public SalesHeader SaleHeaders{ get; set; }
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity()
.HasKey(t => new { t.SalesOrderNo,t.SalesType,t.SalesYear,t.BranchCode });
modelBuilder.Entity()
.HasKey(t => new { t.SalesOrderNo, t.SalesType, t.SalesYear, t.BranchCode,t.SalesLineNo});
modelBuilder.Entity()
.HasOne(e => e.SaleHeaders)
.WithMany(e => e.SalesFooters)
.HasForeignKey(e => e.SalesOrderNo);
}

How to make relation between two models based on keys above ?

4 Replies

Know the answer? Post it — somebody with the same question will find it here.

Jignesh Kumar7y ago
Hi Ahemad,

Please find below link there very good explanation is there

https://www.learnentityframeworkcore.com/configuration/one-to-many-relationship-configuration
ahmed elbarbary7y ago
Thank you for reply
In my case above i lready have more keys on sales header and footer
so that are this possible on entityframework core 2.1 or not
if there are any thing make work around please tell me
Laxmidhar Sahoo7y ago
hi I think your colums are mismatch.
Jignesh Kumar7y ago
Hi ahemad,

I think you should look into this part and you should not mark all column in key(only mark your PK column)
modelBuilder.Entity()
                     .HasOne(e => e.SaleHeaders)
                     .WithMany(e => e.SalesFooters)
                     .HasForeignKey(e => e.SalesOrderNo);
Your salesHeader class should have SalesOrderNo Column field required and
modelBuilder.Entity()
                     .HasRequired(e => e.SalesOrderNo)
                     .WithMany(e => e.SalesFooters)
                     .HasForeignKey(e => e.SalesOrderNo);