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更改数据源 WCF 数据服务

发布于 2024-08-26 09:41:55 字数 79 浏览 10 评论 0原文

有人知道如何动态更改 DataServices 的当前数据源吗？

示例我想咨询服务并传递一个参数说要建立另一个连接，是否可能？

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橘寄 2024-09-02 09:41:55

它应该非常简单，您可以使用一个覆盖方法来创建数据源。

//
// Summary:
//     Creates a data source of the template class that will be used by the data
//     service.
//
// Returns:
//     An instance of the data source.
protected virtual T CreateDataSource();

当被覆盖时，它应该看起来像这样。

protected override MyModel CreateDataSource()
{
    MyModel modal = new MyModal();

    return modal;
}

这将能够创建具有不同连接字符串的数据源。

下面我添加了一系列操作，您可以将此信息传递给 DataService，以便您可以动态更改数据源的连接。

1.请求标头

如果您在 DataServiceContext 上订阅 SendingRequest，则可以在客户端将额外的信息传递给数据服务，这允许您向 Web 请求添加额外的请求标头。例如，完成此操作后，您可以通过访问 CreateDataSource 方法上的 System.Web.HttpContext.Current.Request.Headers 来读取它们。

如果能够访问内部 IDataService 接口就好了，该接口公开了执行此类操作所需的所有信息。

2.查询字符串

不执行 SendingRequest 和标头的另一种方法是添加一个 QueryString 参数，您可以在特定值中检查该参数并相应地初始化数据源。

3.身份

您可以使用用户凭据来选择要使用的数据源。

同样，这些只是关于如何实现数据源选择的想法。

您可以使用上述策略做很多事情，我希望这能回答您的问题，并帮助您解决问题

PS：只要您所说的“更改数据源”的意思是将模型的连接字符串更改为另一个数据库以上将起作用。

It should be really simple there is a override method you can use that creates a data source.

//
// Summary:
//     Creates a data source of the template class that will be used by the data
//     service.
//
// Returns:
//     An instance of the data source.
protected virtual T CreateDataSource();

When overridden it should look like this.

protected override MyModel CreateDataSource()
{
    MyModel modal = new MyModal();

    return modal;
}

That would give the ability to create a data source with a different connection string.

Below I have added a list of things you can do to pass this information to DataService so you can change the connection of your data source on the fly.

1. Request Headers

You can on the client side pass extra information to data services if you subscribe the SendingRequest on the DataServiceContext, which allows you to add extra request headers to your web requests. Once you do that for example you can read them by accessing the System.Web.HttpContext.Current.Request.Headers on the CreateDataSource method.

It would have been nice to be able to get access to the internal IDataService interface which exposes all the information you need to do this sort of thing.

2. Query String

Another way with out doing the SendingRequest and the headers is to add a QueryString parameter that you can check for in the specific value and initialize the data source accordingly.

3. Identity

You can use the users credentials to chose what data source you want to use.

Again these are just ideas about how to achieve this selection of data sources.

You can do a number of things with the strategies above I Hope this answer your question and it helps you with your problem

PS.: as long as what you mean by "change the data source" is change the connection string of your model to another database the above will work.

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