/// <summary>
/// 设置数据库初始化，策略为自动迁移到最新版本
/// </summary>
public static void Initialize()
{
CodeFirstDbContext context = new CodeFirstDbContext();
IDatabaseInitializer <CodeFirstDbContext> initializer;
if (!context.Database.Exists())
{
initializer = new CreateDatabaseIfNotExistsWithSeed();
}
else
{
initializer = new NullDatabaseInitializer <CodeFirstDbContext>();
// initializer = new MigrateDatabaseToLatestVersion<CodeFirstDbContext, MigrationsConfiguration>();
}
Database.SetInitializer(initializer);
//EF预热，解决EF6第一次加载慢的问题
ObjectContext objectContext = ((IObjectContextAdapter)context).ObjectContext;
StorageMappingItemCollection mappingItemCollection = (StorageMappingItemCollection)objectContext.ObjectStateManager
.MetadataWorkspace.GetItemCollection(DataSpace.CSSpace);
mappingItemCollection.GenerateViews(new List <EdmSchemaError>());
context.Dispose();
}
public static ApplicationDbContext Create()
{
IDatabaseInitializer <ApplicationDbContext> strategy;
switch (ConfigurationManager.AppSettings["Database_Initialize_Strategy"])
{
case "CreateDatabaseIfNotExists":
strategy = new CreateDatabaseIfNotExists <ApplicationDbContext>();
break;
case "DropCreateDatabaseAlways":
strategy = new DropCreateDatabaseAlways <ApplicationDbContext>();
break;
case "DropCreateDatabaseIfModelChanges":
strategy = new DropCreateDatabaseIfModelChanges <ApplicationDbContext>();
break;
case "MigrateDatabaseToLatestVersion":
strategy = new MigrateDatabaseToLatestVersion <ApplicationDbContext, Configuration>();
break;
default:
strategy = new NullDatabaseInitializer <ApplicationDbContext>();
break;
}
Database.SetInitializer(strategy);
return(new ApplicationDbContext());
}
public DefaultDbConfiguration()
{
IDatabaseInitializer<DefaultDbContext> databaseInitializer;
if (GlobalConfig.AutomaticMigrationsEnabled)
{
databaseInitializer = new MigrateDatabaseToLatestVersion<DefaultDbContext, Configuration>();
SetContextFactory(typeof(DefaultDbContext), () =>
{
var work = new HttpContextWrapper(HttpContext.Current).Request.RequestContext.GetWorkContext();
return work.Resolve<EntityFrameworkDbContextFactory>().Create();
});
}
else
databaseInitializer = new NullDatabaseInitializer<DefaultDbContext>();
SetDatabaseInitializer(databaseInitializer);
}
public DefaultDbConfiguration()
{
IDatabaseInitializer <DefaultDbContext> databaseInitializer;
if (GlobalConfig.AutomaticMigrationsEnabled)
{
databaseInitializer = new MigrateDatabaseToLatestVersion <DefaultDbContext, Configuration>();
SetContextFactory(typeof(DefaultDbContext), () =>
{
var work = new HttpContextWrapper(HttpContext.Current).Request.RequestContext.GetWorkContext();
return(work.Resolve <EntityFrameworkDbContextFactory>().Create());
});
}
else
{
databaseInitializer = new NullDatabaseInitializer <DefaultDbContext>();
}
SetDatabaseInitializer(databaseInitializer);
}
/// <summary>
/// 初始化
/// </summary>
public static void Init()
{
IDatabaseInitializer <MySqlDbContext> initializer;
if (!Database.Exists(_nameOrConnectionString))
{
//初始化代码放在CreateDatabaseIfNotExists中
//initializer = new CreateDatabaseIfNotExists<MySqlDbContext>();
initializer = new CreateDatabaseIfNotExists <MySqlDbContext>();
}
else
{
//初始化代码不要放在MigrateDatabaseToLatestVersion中
//initializer = new MigrateDatabaseToLatestVersion<MySqlDbContext, MigrationConfiguration>();
//MySql的数据库迁移有bug，不能用
////相当于null，不进行初始化
initializer = new NullDatabaseInitializer <MySqlDbContext>();
}
// The database initializer is called when a the given System.Data.Entity.DbContext type is used to access a database for the first time.
//因为第一次访问数据库时调用Seed来初始化，所以目前检查数据库是否存在并没有调用Seed
Database.SetInitializer(initializer);
}
