我正在使用实体框架代码第一次迁移,我有一个场景,我想运行一套集成测试.每次测试运行时,我想重新创建数据库,并应用所有迁移
步骤应该是：
>删除现有的测试数据库(如果有的话)
>创建一个新的测试数据库,并应用所有迁移
>种子数据
这是我已经将迁移添加到的现有项目,我使用Enable-Migrations命令来创建一个“InitialCreate”迁移,其中包含将所有表添加到我的数据库的代码.
我的自定义IDatabaseInitializer中的代码如下：
public void InitializeDatabase(MyContext context)
{
//delete any existing database,and re-create
context.Database.Delete();
context.Database.Create();
//apply all migrations
var dbMigrator = new DbMigrator(new Configuration());
dbMigrator.Update();
//seed with data
this.Seed(context);
context.SaveChanges();
}
我的InitialCreate迁移的Up方法没有被这段代码调用,这不是我预期的.而是在调用Database.Create()方法时创建所有的表.我需要InitialCreate迁移才能运行,因为我有其他代码来创建存储过程.
解决方法
以下代码允许我满足我在问题中概述的集成测试场景的需求,但肯定有更好的方法？
public void InitializeDatabase(MyContext context)
{
//delete any existing database,and re-create
context.Database.Delete();
var newDbConnString = context.Database.Connection.ConnectionString;
var connStringBuilder = new sqlConnectionStringBuilder(newDbConnString);
var newDbName = connStringBuilder.InitialCatalog;
connStringBuilder.InitialCatalog = "master";
//create the new DB
using(var sqlConn = new sqlConnection(connStringBuilder.ToString()))
{
using (var createDbCmd = sqlConn.CreateCommand())
{
createDbCmd.CommandText = "CREATE DATABASE " + newDbName;
sqlConn.Open();
createDbCmd.ExecuteNonQuery();
}
}
//wait up to 30s for the new DB to be fully created
//this takes about 4s on my desktop
var attempts = 0;
var dbOnline = false;
while (attempts < 30 && !dbOnline)
{
if (IsDatabaSEOnline(newDbConnString))
{
dbOnline = true;
}
else
{
attempts++;
Thread.Sleep(1000);
}
}
if (!dbOnline)
throw new ApplicationException(string.Format("Waited too long for the newly created database \"{0}\" to come online",newDbName));
//apply all migrations
var dbMigrator = new DbMigrator(new Configuration());
dbMigrator.Update();
//seed with data
this.Seed(context);
context.SaveChanges();
}
private bool IsDatabaSEOnline(string connString)
{
try
{
using (var sqlConn = new sqlConnection(connString))
{
sqlConn.Open();
return sqlConn.State == ConnectionState.Open;
}
}
catch (sqlException)
{
return false;
}
}
