EF测试单元成功却数据库没有相应的表是怎么回事?

Question

为新建项目开启一个(asp.net mvc5单页程序)EF的codefirst测试,代码如下:

 var en = new Enterprise
            {
                name = "企业",
                address ="地址",
                legalPerson ="法人名字",
                contactName = "联系人名字",
                contactTel = "联系人电话",
                contactPhone = "联系人手机",
                createTime = DateTime.Now.Date,
                longitude = 111.22f,
                latitude=23.23f
            };
            try
            {
                
                Database.SetInitializer<MyContext>(new DropCreateDatabaseIfModelChanges<MyContext>());
                using (var context = new MyContext())
                {
                    context.enterprises.Add(en);
                    context.SaveChanges();
                }
            }
            catch (Exception e)
            {
                Assert.AreEqual("ok", e.Message);

            }

显示测试成功却在数据库找不到建立的表示怎么回事?
测试的app.config连接串已经配置成和工程web.config一样
<connectionStrings>

<add name="DefaultConnection" connectionString="Data Source=(Local);Initial Catalog=mydb;Integrated Security=True" providerName="System.Data.SqlClient" />

</connectionStrings>