在 Entity Framework Core 2.1 中播种关系数据答案

【问题标题】：Seeding relationship data in Entity Framework Core 2.1在 Entity Framework Core 2.1 中播种关系数据
【发布时间】：2018-07-11 02:09:27
【问题描述】：

根据 .NET Core 文档 (https://docs.microsoft.com/en-us/ef/core/modeling/data-seeding)，我可以在 ModelBuilder 中使用 HasData 播种数据。

但我需要播种一个关系数据，例如：

public class ModuleComponent
{
        public int Id { get; set; }
        public int DisplayOrder { get; set; }
        public string ModuleName { get; set; }        
        public int Level { get; set; }        
        public int? ParentId { get; set; }
        public ModuleComponent Parent { get; set; }
        public ICollection<ModuleComponent> Children {get; set;}
}

在我创建 Seeder 类并从 Program.cs 调用它之前

namespace CRSApp.API.Data
{
    public class SeederModuleComponent
    {
        private readonly DataContext _context;

        public SeederModuleComponent(DataContext context)
        {
            _context = context;
        }

        public void Seeding()
        {
            if (!_context.ModuleComponent.Any())
            {
                // create Admin etc 
                var admin = new ModuleComponent
                {
                    DisplayOrder = 0,
                    ModuleName = "Admin",
                    Level = 0
                };

                var dashboard = new ModuleComponent
                {
                    DisplayOrder = 1,
                    ModuleName = "Dashboard",
                    Level = 0
                };

                var clients = new ModuleComponent
                {
                    DisplayOrder = 2,
                    ModuleName = "Clients",
                    Level = 0
                };

                var timesheet = new ModuleComponent
                {
                    DisplayOrder = 3,
                    ModuleName = "Time Sheet",
                    Level = 0
                };

                var billings = new ModuleComponent
                {
                    DisplayOrder = 3,
                    ModuleName = "Billing",
                    Level = 0
                };

                var reports = new ModuleComponent
                {
                    DisplayOrder = 4,
                    ModuleName = "Reports",
                    Level = 0
                };

                _context.ModuleComponent.Add(admin);
                _context.ModuleComponent.Add(dashboard);
                _context.ModuleComponent.Add(clients);
                _context.ModuleComponent.Add(timesheet);
                _context.ModuleComponent.Add(billings);
                _context.ModuleComponent.Add(reports);

                //ADMIN
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Organisation", Level = 1, DisplayOrder = 0, Parent = admin });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "User Group", Level = 1, DisplayOrder = 1, Parent = admin });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Users", Level = 1, DisplayOrder = 2, Parent = admin });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "All Entitlements", Level = 1, DisplayOrder = 3, Parent = admin });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Staff Leave Approval", Level = 1, DisplayOrder = 4, Parent = admin });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Settings", Level = 1, DisplayOrder = 5, Parent = admin });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Department Productivity", Level = 1, DisplayOrder = 6, Parent = admin });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Staff Productivity Chart", Level = 1, DisplayOrder = 7, Parent = admin });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Job Profitability", Level = 1, DisplayOrder = 8, Parent = admin });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Activity Codes", Level = 1, DisplayOrder = 9, Parent = admin });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Master Password", Level = 1, DisplayOrder = 10, Parent = admin });

                //Dashboard
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Summary of Active Clients", Level = 1, DisplayOrder = 0, Parent = dashboard });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Practice Work In Progress", Level = 1, DisplayOrder = 1, Parent = dashboard });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Employee Productivity", Level = 1, DisplayOrder = 2, Parent = dashboard });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Leave", Level = 1, DisplayOrder = 3, Parent = dashboard });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Staff Default Rates", Level = 1, DisplayOrder = 4, Parent = dashboard });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Activity Codes", Level = 1, DisplayOrder = 5, Parent = dashboard });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Change Password", Level = 1, DisplayOrder = 6, Parent = dashboard });

                // Clients
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Clients Active Case", Level = 1, DisplayOrder = 0, Parent = clients });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Client Personal", Level = 1, DisplayOrder = 1, Parent = clients });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Client Company", Level = 1, DisplayOrder = 2, Parent = clients });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "My Clients Profile", Level = 1, DisplayOrder = 3, Parent = clients });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "All Clients Profile", Level = 1, DisplayOrder = 4, Parent = clients });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Hourly Rate Assigned", Level = 1, DisplayOrder = 5, Parent = clients });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Edit Hourly Rate Assigned", Level = 1, DisplayOrder = 6, Parent = clients });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Reassigning Clients", Level = 1, DisplayOrder = 7, Parent = clients });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "WIP Pre Billed", Level = 1, DisplayOrder = 8, Parent = clients });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "My Client Billing History", Level = 1, DisplayOrder = 9, Parent = clients });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "All Client Billing History", Level = 1, DisplayOrder = 10, Parent = clients });

                //Timesheet
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Create New Timesheet", Level = 1, DisplayOrder = 0, Parent = timesheet });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "My Timesheets", Level = 1, DisplayOrder = 1, Parent = timesheet });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "All Employee Timesheets", Level = 1, DisplayOrder = 2, Parent = timesheet });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Approve/Reject Timesheets", Level = 1, DisplayOrder = 3, Parent = timesheet });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Create Expense Sheet", Level = 1, DisplayOrder = 4, Parent = timesheet });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "My Expense Sheets", Level = 1, DisplayOrder = 5, Parent = timesheet });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "All Employee Expense Sheets", Level = 1, DisplayOrder = 6, Parent = timesheet });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Approve/Reject Expense Sheet", Level = 1, DisplayOrder = 7, Parent = timesheet });

                // Billings
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Create New Bill", Level = 1, DisplayOrder = 0, Parent = billings });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "My Billing", Level = 1, DisplayOrder = 1, Parent = billings });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "All Billing History", Level = 1, DisplayOrder = 2, Parent = billings });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Approve/Reject Bill", Level = 1, DisplayOrder = 3, Parent = billings });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "My Potentials", Level = 1, DisplayOrder = 4, Parent = billings });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Create New Potential", Level = 1, DisplayOrder = 5, Parent = billings });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "All Potentials", Level = 1, DisplayOrder = 6, Parent = billings });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "My Batch Billing", Level = 1, DisplayOrder = 7, Parent = billings });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "All Batch Billing", Level = 1, DisplayOrder = 8, Parent = billings });

                //Reports
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Timesheet Analysis Report", Level = 1, DisplayOrder = 0, Parent = reports });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "WIP Client Report", Level = 1, DisplayOrder = 1, Parent = reports });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "WIP Practice Report", Level = 1, DisplayOrder = 2, Parent = reports });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "My Report", Level = 1, DisplayOrder = 3, Parent = reports });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "All Employee Report", Level = 1, DisplayOrder = 4, Parent = reports });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "My Client Analysis Report", Level = 1, DisplayOrder = 5, Parent = reports });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "All Client Analysis Report", Level = 1, DisplayOrder = 6, Parent = reports });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Create Summary Remuneration Report", Level = 1, DisplayOrder = 7, Parent = reports });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "All Summary Remun. Report", Level = 1, DisplayOrder = 8, Parent = reports });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Create Detailed Remun. Report", Level = 1, DisplayOrder = 9, Parent = reports });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "All Detailed Remun. Report", Level = 1, DisplayOrder = 10, Parent = reports });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Create Summary Expense Report", Level = 1, DisplayOrder = 11, Parent = reports });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "All Summary Expense Report", Level = 1, DisplayOrder = 12, Parent = reports });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "Create Detailed Expense Report", Level = 1, DisplayOrder = 13, Parent = reports });
                _context.ModuleComponent.Add(new ModuleComponent { ModuleName = "All Detailed Expense Report", Level = 1, DisplayOrder = 14, Parent = reports });

                _context.SaveChanges();
            }
        }
    }
}

如何使用 EF Core 2.1 ？因为我们可能不知道对象的 parentId。

谢谢

【问题讨论】：

您是否得到了不是 ModuleComponent 的 parentId 的意外结果？我用你的代码做了一个测试，它工作正常，ParentId 是自动设置的。
上面的代码有效。但是如何使用 HasData() 来做到这一点，它只接受对象数组。
您可以查看我的答案以使用HasData()。
谢谢爱德华。我从 Microsoft 文档中找到了答案，但您的解决方案似乎也不错。

标签： c# .net-core asp.net-core-2.0 ef-core-2.1

【解决方案1】：

对于HasData()，您需要提供ModuleComponent[] 并显式设置Id 和ParentId。

这是一个演示代码：

    public class SeederData
{
    public static ModuleComponent[] SeederModuleArray()
    {
        int index = 1;
        var result = new List<ModuleComponent>();
        var admin = new ModuleComponent
        {
            Id = index,
            DisplayOrder = 0,
            ModuleName = "Admin",
            Level = 0
        };
        result.Add(admin);
        var dashboard = new ModuleComponent
        {
            Id = ++index,
            DisplayOrder = 1,
            ModuleName = "Dashboard",
            Level = 0
        };
        result.Add(dashboard);
        var Organisation = new ModuleComponent
        {
            Id = ++index,
            ModuleName = "Organisation",
            Level = 1,
            DisplayOrder = 0,
            ParentId = admin.Id
        };
        result.Add(Organisation);
        var Leave = new ModuleComponent
        {
            Id = ++index,
            ModuleName = "Leave",
            Level = 1,
            DisplayOrder = 3,
            ParentId = dashboard.Id
        };
        result.Add(Leave);
        return result.ToArray();
    }
}

在DbContext 中使用ModuleComponent[]

            builder.Entity<ModuleComponent>().HasData(
            SeederData.SeederModuleArray()
        );

【讨论】：