![](/img/trans.png)
[英]EF 6 Code First Migration after deleting data from __MigrationHistory table
[英]cannot insert data in table manually through server explorer in visual studio when code first migration is used
由於標記了此遷移,因此您似乎試圖將數據獲取到表中,該機制稱為“ 種子” 。 您可以像這樣覆蓋Seed()方法:
protected override void Seed(MyDbContext context)
{
context.Customers.AddOrUpdate(
c => c.Name, // Use Name (or some other unique field) instead of Id
new Customer
{
Name = "Customer 1",
IsSubscribed = false,
MembershipTypeId = 1 // A value from MembershipType table
},
new Customer
{
Name = "Customer 2",
IsSubscribed = true,
MembershipTypeId = 2 // A value from MembershipType table
});
context.SaveChanges();
}
現在,當您運行update-database
此代碼將運行,並且如果客戶不在數據庫中,則會將其添加。 如果刪除數據庫,則下次運行遷移時將添加它們。
如果只想手動插入,則需要在該列中提供有效的MembershipTypeId(在MembershipType表中搜索有效值)。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.