连接数据源之间的选择 C#

发布于 2024-10-26 07:15:58 字数 537 浏览 6 评论 0原文

我的表单上有一个 dataAdapter、dataSet 和 BindingSource，用于连接到 SQL 数据库以显示表单中的数据，一切正常。但是，我需要有两个连接服务器的选项。例如 ISSP\SQLEXPRESS 和 MY-WEB。我不知道该怎么做，想知道是否有人可以给我一些帮助，从哪里开始？谢谢：）但是当使用变量时它说它无法连接。

我正在使用下面的代码，但它说它无法连接，所以我想知道我是否引用了错误的变量？

sqlConnectionNW.ConnectionString = "Data Source=@server;Initial Catalog=Northwind;Integrated Security=True";

当我将代码更改为以下内容时，它可以完美运行。

sqlConnectionNW.ConnectionString = "Data Source=ISSP\SQLEXPRESS;Initial Catalog=Northwind;Integrated Security=True";

原文

I've got a dataAdapter, dataSet and BindingSource on my forms to connect to an SQL database to show the data in the form, and it all works fine. However, I need to have 2 options of what server to connect to.
e.g ISSP\SQLEXPRESS and MY-WEB.
I don't know how to do this and wondered whether anyone could give me some help on where to start? Thanks :)
But when using the variables it says that it can't connect.

I'm using the code below but it says that it can't connect, so i'm wondering whether i'm refering to the variable wrong?

sqlConnectionNW.ConnectionString = "Data Source=@server;Initial Catalog=Northwind;Integrated Security=True";

When I change the code to the following, it works perfectly.

sqlConnectionNW.ConnectionString = "Data Source=ISSP\SQLEXPRESS;Initial Catalog=Northwind;Integrated Security=True";

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复古式 2024-11-02 07:15:58

首先将两个连接设置添加到您的应用程序配置文件中：

<connectionStrings>
    <add name="Test"
     connectionString="Data Source=ISSP\SQLEXPRESS;Initial Catalog=myDataBase;User Id=myUsername;Password=myPassword;"
     providerName="System.Data.SqlClient" />
    <add name="Production"
     connectionString="Data Source=MY-WEB;Initial Catalog=myDataBase;User Id=myUsername;Password=myPassword;"
     providerName="System.Data.SqlClient" />
</connectionStrings>

在您的应用程序中，将一个组合框添加到表单中（在本例中称为 uiConnection），然后添加以下代码来填充它：

uiConnection.ValueMember = "Name";
foreach (ConnectionStringSettings con in ConfigurationManager.ConnectionStrings)
    {
        uiConnection.Items.Add(con);
    }

您现在可以使用下拉列表来指定要连接的数据库到。当您获取数据时，请执行以下操作以获得正确的连接字符串：

ConnectionStringSettings connection = uiConnection.SelectedItem as ConnectionStringSettings
string queryString = "SELECT CustomerID, CompanyName FROM dbo.Customers";
SqlDataAdapter adapter = new SqlDataAdapter(queryString, connection);
DataSet customers = new DataSet();
adapter.Fill(customers, "Customers");

Firstly add both connection settings to your app config file:

<connectionStrings>
    <add name="Test"
     connectionString="Data Source=ISSP\SQLEXPRESS;Initial Catalog=myDataBase;User Id=myUsername;Password=myPassword;"
     providerName="System.Data.SqlClient" />
    <add name="Production"
     connectionString="Data Source=MY-WEB;Initial Catalog=myDataBase;User Id=myUsername;Password=myPassword;"
     providerName="System.Data.SqlClient" />
</connectionStrings>

In your application add a ComboBox to the form and (called uiConnection in this example) and add the following code to populate it:

uiConnection.ValueMember = "Name";
foreach (ConnectionStringSettings con in ConfigurationManager.ConnectionStrings)
    {
        uiConnection.Items.Add(con);
    }

You can now use the drop down to specify which database to connect to. When you fetch your data do the following to get the correct connection string:

ConnectionStringSettings connection = uiConnection.SelectedItem as ConnectionStringSettings
string queryString = "SELECT CustomerID, CompanyName FROM dbo.Customers";
SqlDataAdapter adapter = new SqlDataAdapter(queryString, connection);
DataSet customers = new DataSet();
adapter.Fill(customers, "Customers");

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