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如何在实体框架连接上更改数据库

entity-framework-4 c#-4.0 .net-4.0 asp.net-mvc-2

2

Johan Olsson · 技术社区 · 15 年前

// This results in a exception, "Specified method is not supported".
private MyEntities _db = new MyEntities();

public IQueryable<MyObject> GetMyObjects(string database)
{
    _db.Connection.ChangeDatabase(database);

    return _db.MyObjects
}

// This works...
private MyEntities _db;
private string entityConnectionString = ConfigurationManager.ConnectionStrings["MyEntities"].ConnectionString;

public IQueryable<MyObject> GetMyObjects(string database)
{
    _db = new MyEntities(entityConnectionString.Replace("__REPLACE_ME__", database));

    return _db.MyObjects
}

1 回复 | 直到 15 年前

1

4

Craig Stuntz 15 年前

我可能会修改你的“这行…”版本,像这样:

private MyEntities _db;
private string entityConnectionString = ConfigurationManager.ConnectionStrings["MyEntities"].ConnectionString;

public IQueryable<MyObject> GetMyObjects(string database)
{
    var ecsb = new EntityConnectionStringBuilder(entityConnectionString);
    var scsb = new SqlConnectionStringBuilder(ecsb.ProviderConnectionString)
    scsb.InitialCatalog = database;
    ecsb.ProviderConnectionString = scsb.ToString();
    _db = new MyEntities(ecsb.ToString());    
    return _db.MyObjects
}