I have a problem when I'm going to Communicate between two table in Ef core and relation is one to many. I want to solve it without change type primary key.my error message is below

The relationship from 'TMSGCategory.TemporaryMessage' to 'TemporaryMessage.TMSGCategories' with foreign key properties {'MsgCategoryId' : short} cannot target the primary key {'Id' : int} because it is not compatible. Configure a principal key or a set of compatible foreign key properties for this relationship.

public class TemporaryMessageConfiguration:IEntityTypeConfiguration<TemporaryMessage>
{
    public void Configure(EntityTypeBuilder<TemporaryMessage> builder)
    {
        builder.HasKey(x => x.Id);

        builder.HasMany(a => a.TMSGCategories).WithOne(a => 
        a.TemporaryMessage).HasForeignKey(a => a.MsgCategoryId);
        
    }
}
public class TMSGCategoryConfiguration:IEntityTypeConfiguration<TMSGCategory>
{
    public void Configure(EntityTypeBuilder<TMSGCategory> builder)
    {   
        builder.HasKey(x => x.MsgCategoryId);
        builder.HasOne(a => a.TemporaryMessage).WithMany(a => a.TMSGCategories);
    }
}

CodePudding user response：

you can set TemporaryMessage.MsgCategoryId and TMSGCategories.Id to int16 in code first and problem solve. You cannot convert int to int16 and both data type must be same in efcore relationship.