Question

我正在使用Entity Framework Core 2.1，并希望使用IDENTITY_INSERT插入一些数据。尽管我将IDENTITY_INSERT设置为On，但在行identityContext.SaveChanges();上仍然出现异常：

Microsoft.EntityFrameworkCore.DbUpdateException：'发生了错误   在更新条目时。有关详细信息，请参见内部异常。'

内部异常

SqlException：无法为以下项插入显式值   IDENTITY_INSERT设置为'ClientGroups'表中的标识列   关闭。

这是我的代码：

using (var identityContext = new IdentityDatabase(identityOptions))
{
    Console.WriteLine("Settings Identity Insert on");
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.ClientGroups ON");
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.Clients ON");
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.ModulePermissions ON");
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.Roles ON");
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.Users ON");

    identityContext.Clients.AddRange(identityclients);
    identityContext.ClientGroups.AddRange(identityClientGroups);
    identityContext.ClientGroupAssociations.AddRange(identityClientGroupAssociations);
    identityContext.AuthClients.AddRange(identityAuthClients);
    identityContext.Roles.AddRange(identityRoles);
    identityContext.Users.AddRange(identityUsers);
    identityContext.UserRoles.AddRange(identityUserRoles);
    identityContext.ModulePermissions.AddRange(identityModulePermissions);
    Console.WriteLine("Saving Data to .identity Database");
    identityContext.SaveChanges();

    Console.WriteLine("Setting Identity Insert off");
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.ClientGroups OFF");
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.Clients OFF");
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.ModulePermissions OFF");
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.Roles OFF");
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.Users OFF");
}

我打开了登录功能，可以看到命令已发送到数据库：

信息：Microsoft.EntityFrameworkCore.Database.Command [20101] 执行的DbCommand（1ms）[Parameters = []，CommandType ='Text'，CommandTimeout = '30'] SET IDENTITY_INSERT dbo.ClientGroups ON信息：Microsoft.EntityFrameworkCore.Database.Command [20101] 已执行DbCommand（0ms）[Parameters = []，CommandType ='Text'，CommandTimeout = '30'] SET IDENTITY_INSERT dbo.Clients上的信息：Microsoft.EntityFrameworkCore.Database.Command [20101] 已执行DbCommand（0ms）[Parameters = []，CommandType ='Text'，CommandTimeout = '30'] SET IDENTITY_INSERT dbo.ModulePermissions ON信息：Microsoft.EntityFrameworkCore.Database.Command [20101] 已执行DbCommand（0ms）[Parameters = []，CommandType ='Text'，CommandTimeout = '30'] SET IDENTITY_INSERT dbo.Roles ON信息：Microsoft.EntityFrameworkCore.Database.Command [20101] 已执行DbCommand（0ms）[Parameters = []，CommandType ='Text'，CommandTimeout = '30'] 设置IDENTITY_INSERT dbo。用户开启

Answer 1

EF Core为每个与数据库相关的操作打开/关闭连接，因此使用ExecuteSqlCommand设置身份无效。

您需要在整个过程中明确保持连接打开：

identityContext.Database.OpenConnection();
try
{
    // your code …
}    
finally
{
    identityContext.Database.CloseConnection();
}

或将整个过程包装在显式事务中：

using (var transaction = identityContext.Database.BeginTransaction())
{
    // your code …
    transaction.Commit();
}

Answer 2

这是@ damien-the-unbeliever的评论和@ivan stoev的建议答案的组合

您一次只能为一张桌子打开IDENTITY_INSERT

必须将代码包装在事务中，因为否则EF Core将使用单独的连接。

使用（var identityContext = new IdentityDatabase（identityOptions）） { 使用（var transaction = identityContext.Database.BeginTransaction（）） { Console.WriteLine（“插入AuthClients”）; identityContext.AuthClients.AddRange（identityAuthClients）; identityContext.SaveChanges（）;

    Console.WriteLine("Inserting ClientGroups");
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.ClientGroups ON");
    identityContext.ClientGroups.AddRange(identityClientGroups);
    identityContext.SaveChanges();
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.ClientGroups OFF");

    Console.WriteLine("Inserting Clients");
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.Clients ON");
    identityContext.Clients.AddRange(identityclients);
    identityContext.SaveChanges();
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.Clients OFF");

    Console.WriteLine("Inserting ClientGroupAssociations");
    identityContext.ClientGroupAssociations.AddRange(identityClientGroupAssociations);
    identityContext.SaveChanges();

    Console.WriteLine("Inserting Users");
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.Users ON");
    identityContext.Users.AddRange(identityUsers);
    identityContext.SaveChanges();
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.Users OFF");

    Console.WriteLine("Inserting Roles");
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.Roles ON");
    identityContext.Roles.AddRange(identityRoles);
    identityContext.SaveChanges();
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.Roles OFF");

    Console.WriteLine("Inserting UserRoles");
    identityContext.UserRoles.AddRange(identityUserRoles);
    identityContext.SaveChanges();

    Console.WriteLine("Inserting ModulePermissions");
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.ModulePermissions ON");
    identityContext.ModulePermissions.AddRange(identityModulePermissions);
    identityContext.SaveChanges();
    identityContext.Database.ExecuteSqlCommand("SET IDENTITY_INSERT dbo.ModulePermissions OFF");

    Console.WriteLine("Commiting transaction");
    transaction.Commit();
}

}

EF核心“无法为标识列插入显式值”，尽管IDENTIY_INSERT设置为ON

2 个答案: