I want to create 2 tables: Team, Match, where in the Match table there are 2 references to the Team table. When I try to generate a database, I get an error related to cascade deletion. Can you tell me how to solve the problem?
public class Team { public int Id { get; set; } public string Name { get; set; } } public class Match { public int Id { get; set; } public int? HomeId { get; set; } public int? GuestId { get; set; } public Team Home { get; set; } public Team Guest { get; set; } } 
First, you need to set the navigation properties to the end:
public class Team { public int Id { get; set; } public string Name { get; set; } public virtual IEnumerable<Match> HomeMatches { get; set; } public virtual IEnumerable<Match> GuestMatches { get; set; } } public class Match { public int Id { get; set; } public int HomeId { get; set; } public int GuestId { get; set; } public Team Home { get; set; } public Team Guest { get; set; } } Secondly, in ApplicationDbContext add:
protected override void OnModelCreating(ModelBuilder builder) { base.OnModelCreating(builder); builder.Entity<Match>() .HasOne(m => m.Home) .WithMany(t => t.HomeMatches) .OnDelete(DeleteBehavior.Restrict); builder.Entity<Match>() .HasOne(m => m.Guest) .WithMany(t => t.GuestMatches) .OnDelete(DeleteBehavior.Restrict); } (Formally, one cascade would be enough to disconnect)
There are details on the metaint: https://metanit.com/sharp/entityframeworkcore/3.2.php
Source: https://ru.stackoverflow.com/questions/840761/
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.OnDelete(DeleteBehavior.Restrict)in modelBinder. Theory here: metanit.com/sharp/entityframeworkcore/3.2.php - AK ♦