Question

模型是成员有很多玩家（一对多Relationshiphip）玩家有很多运动体育有很多球员 PlayerSports与玩家和体育之间的多对多关系

public class Member
{
    public int MemberId { get; set; }
    public string Code { get; set; }
    public double Payment { get; set; }
    public virtual List<Player> Players { get; set; }
}

public class Player
{
    public int PlayerId { get; set; }
    public string Name { get; set; }
    public double Payment { get; set; }
    public virtual ICollection<PlayerSport> PlayerSports { get; set; }
    public int MemberId { get; set; }
    public virtual Member Member { get; set; }
}

public class Sport
{
    public int SportId { get; set; }
    public string Name { get; set; }
    public string Type { get; set; }
    public double Price { get; set; }
    public virtual ICollection<PlayerSport> PlayerSports { get; set; }
}

public class PlayerSport
{
    public int PlayerId { get; set; }
    public int SportId { get; set; }
    public virtual Player Player { get; set; }
    public virtual Sport Sport { get; set; }
}

当成员被删除时，删除子级球员而不删除运动删除播放器后，其父级成员和体育项目仍然相同

    public class AppContext : DbContext
    {
        public DbSet<Member> Members { get; set; }
        public DbSet<Player> Players { get; set; }
        public DbSet<Sport> Sports { get; set; }
        public DbSet<PlayerSport> PlayersSports { get; set; }

    public AppContext()
    {
        SQLitePCL.Batteries_V2.Init();

        this.Database.EnsureCreated();
    }
    
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

        modelBuilder.Entity<Member>()
            .HasMany<Player>(m => m.Players)
            .WithOne(p => p.Member)
            .HasForeignKey(p => p.MemberId)
            .OnDelete(DeleteBehavior.Cascade);

        modelBuilder.Entity<PlayerSport>()
            .HasKey(t => new { t.PlayerId, t.SportId });

        modelBuilder.Entity<PlayerSport>()
        .HasOne(ps => ps.Player)
        .WithMany(p => p.PlayerSports)
        .HasForeignKey(ps => ps.PlayerId);

        modelBuilder.Entity<PlayerSport>()
            .HasOne(ps => ps.Sport)
            .WithMany(s => s.PlayerSports)
            .HasForeignKey(ps => ps.SportId);
    }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        string dbPath = Path.Combine(FileSystem.AppDataDirectory, "members.db3");

        optionsBuilder
            .UseSqlite($"Filename={dbPath}");
    }
}

保存条目并调用SaveChangesAsync时出现错误

内部异常：Microsoft.Data.Sqlite.SqliteException（0x80004005）： SQLite错误19：“ FOREIGN KEY约束失败”。

FullError：

内部异常：Microsoft.Data.Sqlite.SqliteException（0x80004005）： SQLite错误19：“ FOREIGN KEY约束失败”。在 Microsoft.Data.Sqlite.SqliteException.ThrowExceptionForRC （System.Int32 rc，SQLitePCL.sqlite3 db）[0x0006d]在：0处 Microsoft.Data.Sqlite.SqliteDataReader.NextResult（）[0x0017b]在：0处 Microsoft.Data.Sqlite.SqliteCommand.ExecuteReader （System.Data.CommandBehavior行为）在[0x000d4]中：0处 Microsoft.Data.Sqlite.SqliteCommand.ExecuteReaderAsync （System.Data.CommandBehavior行为， System.Threading.CancellationToken cancellingToken）[0x00007]在：0处 Microsoft.Data.Sqlite.SqliteCommand.ExecuteDbDataReaderAsync （System.Data.CommandBehavior行为， System.Threading.CancellationToken cancellingToken）[0x00011]在：0处 Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync （Microsoft.EntityFrameworkCore.Storage.RelationalCommandParameterObject parameterObject，System.Threading.CancellationToken cancelledToken） [0x00278]在<908a85714c18433696ab2103bcabebcc>：0中 Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync （Microsoft.EntityFrameworkCore.Storage.RelationalCommandParameterObject parameterObject，System.Threading.CancellationToken cancelledToken） [0x004c9]在<908a85714c18433696ab2103bcabebcc>：0中 Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync （Microsoft.EntityFrameworkCore.Storage.RelationalCommandParameterObject parameterObject，System.Threading.CancellationToken cancelledToken） [0x0057b]在<908a85714c18433696ab2103bcabebcc>：0中 Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync （Microsoft.EntityFrameworkCore.Storage.IRelationalConnection 连接，System.Threading.CancellationToken取消令牌） <908a85714c18433696ab2103bcabebcc>：0
中的[0x000cc]

将xamarin与EF核心一起使用会产生SQLite错误

0 个答案: