Entity framework 实体框架迁移种子重复行
我有两节课Entity framework 实体框架迁移种子重复行,entity-framework,entity-framework-migrations,Entity Framework,Entity Framework Migrations,我有两节课 public class Category { public int Id { get; set; } public string Name { get; set; } } public class Item { public int Id { get; set; } public sting Name { get; set; } public Category Category { get; set; } } 我有EF迁移和以下种子: var instock
public class Category
{
public int Id { get; set; }
public string Name { get; set; }
}
public class Item
{
public int Id { get; set; }
public sting Name { get; set; }
public Category Category { get; set; }
}
我有EF迁移和以下种子:
var instockCategory = new Category() { Name = "InStock" };
var outofStockCategory = new Category() { Name = "OutOfStock" };
context.Items.AddOrUpdate(
d => d.Name,
new Item() { Name = "Item1", Category = instockCategory },
new Item() { Name = "Item2", Category = outofStockCategory },
new Item() { Name = "Item3", Category = outofStockCategory }
);
行“d=>d.Name”确保基于项的名称,在我为数据库重新设定种子时不会有重复的记录。
但是,在我第一次执行此操作时,创建了id为1和2的两个类别。但第二次运行时,创建了3个新类别!
我可以在不先手动添加每个类别的情况下修复此问题吗?您也必须对您的类别使用
addor update
var instockCategory = default(Category);
var outofStockCategory = default(Category);
context.Set<Category>().AddOrUpdate(
c => c.Name,
instockCategory = new Category() { Name = "InStock" },
outofStockCategory = new Category() { Name = "OutOfStock" }
);
context.Items.AddOrUpdate(
d => d.Name,
new Item() { Name = "Item1", Category = instockCategory },
new Item() { Name = "Item2", Category = outofStockCategory },
new Item() { Name = "Item3", Category = outofStockCategory }
);
可能吧,但我不想,因为那时我必须添加一个Categories DbSet,而现在我没有它。我仍然可以做,只是问问是否还有其他可能。@DennisvanderStelt更新的答案有帮助吗?“添加类别数据库集”的确切含义是什么?
public class Context : DbContext
{
public DbSet<Item> Items { get; set; }
}