首先是实体框架代码-使其“创建架构"没有删除数据库? [英] Entity Framework code first - make it do "CREATE SCHEMA" without a drop database?

问题描述

我正在尝试改善数据整合性能，统一备份，允许单独的项目在一个数据库中使用单独的架构.

I am trying to do better data consolidation performance & backup unity by, allowing separate project to use separate schema within one database.

但是我很困惑，实体框架在它的一个Database.Create()函数中执行两个问题-创建数据库然后创建表对象.

But I am stuck and the point where entity framework performs two concerns - database creation then table object creation - within its one Database.Create() function.

有没有一种方法可以只获取表对象创建活动而无需重新创建数据库?我希望每个项目共享一个数据库，但具有明确定义的架构所有权.

Is there a way to just get the table object creation activity without database re-creation? I hope to have every project sharing one database but with well defined schema ownership.

此代码的主要项目是首先使用代码，因此我们的团队可以同时处理模型的各个部分.另外，该项目不使用迁移，因为我们已经在生产的所有部署中使用了智能默认设置.

下面是我到目前为止创建的代码."//TODO:"部分就是我遇到的问题.

Below is the code I have created so far. The "//TODO:" part is where I am stuck.

问候伊恩

namespace app1.Models
{
    using System;
    using System.Data.Entity;
    using System.Data.Entity.Infrastructure.Interception;
    using System.Diagnostics;
    using System.Linq;

    public class Model1 : DbContext
    {
        public Model1()
            : base("name=Model1")
        {
            // Log database activity
            this.Database.Log = DebugWrite;
        }
        private void DebugWrite(string s) { Debug.Write(s); } // Avoiding Compiler Error CS1618

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            modelBuilder.HasDefaultSchema("b1");
            base.OnModelCreating(modelBuilder);
        }

        //public virtual DbSet<blog1> blog1 { get; set; }
        //public virtual DbSet<common> common { get; set; }
    }


    public class DbB1SchemaInitializer : IDatabaseInitializer<Model1>
    {
        public void InitializeDatabase(Model1 context)
        {
            context.Database.Log = DebugWrite;

            if (context.Database.Exists())
            {
                if (!context.Database.CompatibleWithModel(true))
                {
                    context.Database.Delete();  // TODO: remove this and make delete the schema and its objects
                    context.Database.Create();  // TODO: remove this and make delete the schema and its objects

                    // Reinstall, create schema and application role.
                    context.Database.ExecuteSqlCommand("CREATE SCHEMA b1");
                    context.Database.ExecuteSqlCommand("CREATE APPLICATION ROLE blog1 WITH PASSWORD = 'Pwd0123456', DEFAULT_SCHEMA = b1");
                    context.Database.ExecuteSqlCommand("GRANT SELECT, UPDATE, INSERT, DELETE, EXECUTE on SCHEMA::b1 to blog1");
                }
            }
            else
            {
                // Fresh install, create the database, schema and application role.
                context.Database.Create(); // Create will make database and make the tables.
                context.Database.ExecuteSqlCommand("CREATE APPLICATION ROLE blog1 WITH PASSWORD = 'Pwd0123456', DEFAULT_SCHEMA = b1");
                context.Database.ExecuteSqlCommand("GRANT SELECT, UPDATE, INSERT, DELETE, EXECUTE on SCHEMA::b1 to blog1");
            }

            // Do database connection interception so database application security is used rather than database user security from this point on.
            //DbInterception.Add(new EFDBConnectionApplicationRoleInterception("blog1", "Pwd0123456"));
        }
        private void DebugWrite(string s) { Debug.Write(s); } // Avoiding Compiler Error CS1618
    }
}

推荐答案

对我来说，为什么要这样做尚不十分清楚，但是如果重新创建架构是问题所在，也许可以为您提供帮助:

Its not totally clear to me why you want to do this, but if the recreation of the schema is the issue, maybe this can help you:

var command = "IF (NOT EXISTS (SELECT * FROM sys.schemas WHERE name = N'b1')) " +
            "BEGIN" +
            "  EXEC ('CREATE SCHEMA B1');" +
            "  EXEC ('CREATE APPLICATION ROLE blog1 WITH PASSWORD = ''Pwd0123456'', DEFAULT_SCHEMA = b1');" +
            "  EXEC ('GRANT SELECT, UPDATE, INSERT, DELETE, EXECUTE on SCHEMA::b1 to blog1');" +
            "END";
context.Database.ExecuteSqlCommand(command);

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