EntityFramework代码优先的自定义连接字符串和迁移

Question

当我使用默认的连接字符串（从中读取app.config）创建上下文时，将创建数据库并进行迁移-基本上，所有操作都是有序的。而以编程方式（使用SqlConnectionStringBuilder）创建连接字符串时：

当数据库不存在时，不会创建数据库（场景A）；

CreateDbIfNotExists()创建数据库模型的最新版本，但不调用迁移机制（场景B）。

在A明显- -一个异常时，我希望访问数据库，抛出它不存在。在B数据库中创建的迁移机制没有正确调用，就像标准连接字符串中那样。

app.config：“ Data Source=localhost\\SQLEXPRESS;Initial Catalog=Db13;User ID=xxx;Password=xxx”

建造者：

sqlBuilder.DataSource = x.DbHost;

sqlBuilder.InitialCatalog = x.DbName;

sqlBuilder.UserID = x.DbUser;

sqlBuilder.Password = x.DbPassword;

初始值设定项：

Database.SetInitializer(

    new MigrateDatabaseToLatestVersion<

        MyContext,

        Migrations.Configuration

    >()

);

规格：实体框架：5.0，数据库：SQL Server Express 2008

Answer 1

如果您的迁移无法正常进行，请尝试Database.Initialize(true)在DbContext ctor中进行设置。public CustomContext(DbConnection connection): base(connection, true)&nbsp; &nbsp;&nbsp;{&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; Database.Initialize(true);&nbsp; &nbsp;&nbsp;}&nbsp; &nbsp;&nbsp;我在迁移中也遇到类似的问题。在我的解决方案中，我必须始终在ctor中设置数据库初始化程序，如下所示public CustomContext(DbConnection connection): base(connection, true)&nbsp; &nbsp;&nbsp;{&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; Database.SetInitializer(new CustomInitializer());&nbsp; &nbsp; &nbsp; &nbsp; Database.Initialize(true);&nbsp; &nbsp;&nbsp;}&nbsp; &nbsp;&nbsp;在自定义初始化程序中，您必须实现InitalizeDatabase(CustomContex context)方法，例如。class CustomInitializer : IDatabaseInitializer<CustomContext>{&nbsp; &nbsp; public void InitializeDatabase(CustomContext context)&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; if (!context.Database.Exists || !context.Database.CompatibleWithModel(false))&nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; var configuration = new Configuration();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; var migrator = new DbMigrator(configuration);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; migrator.Configuration.TargetDatabase = new DbConnectionInfo(context.Database.Connection.ConnectionString, "System.Data.SqlClient");&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; var migrations = migrator.GetPendingMigrations();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if (migrations.Any())&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; var scriptor = new MigratorScriptingDecorator(migrator);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; string script = scriptor.ScriptUpdate(null, migrations.Last());&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if (!String.IsNullOrEmpty(script))&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; context.Database.ExecuteSqlCommand(script);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }}