Question

我也是C＃和OOP的新手，我正在创建一个DB类来连接SQL Server。你能帮我创建一个连接函数并解释如何以多种形式重用它吗？我看过http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection.aspx的一个函数，但我不确定如何以另一种形式使用它。

此致 Touseef

Answer 1

using System.Data.SqlClient;
//
    // First access the connection string, which may be autogenerated in Visual Studio for you.
    //
    string connectionString = "Write your sql connection string"
    //
    // In a using statement, acquire the SqlConnection as a resource.
    //
    using (SqlConnection con = new SqlConnection(connectionString))
    {
        //
        // Open the SqlConnection.
        //
        con.Open();
        //
        // The following code shows how you can use an SqlCommand based on the SqlConnection.
        //
        using (SqlCommand command = new SqlCommand("SELECT TOP 2 * FROM Dogs1", con))
        using (SqlDataReader reader = command.ExecuteReader())
        {
        while (reader.Read())
        {
            // process it
        }
        }
    }

修改使用此链接获取详细信息教程 http://www.codeproject.com/KB/database/sql_in_csharp.aspx

Answer 2

利用：C#: Microsoft Enterprise Library: Data Access

要在第二个表单上建立连接，您需要关闭第一个连接，然后在另一个连接上创建新连接以获取数据。

Answer 3

Here are few code samples to get you going :

Establish the connection with SQL

string connectionString = "Data Source=myServerAddress;Initial Catalog=myDataBase;User Id=myUsername;Password=myPassword;";
SqlConnection con = new SqlConnection(connectionString);
con.Open();

//Database operations

con.Close();

Fetch the data from Database :

string queryString = "SELECT Column1, Column2 FROM TableName";
SqlDataAdapter adapter = new SqlDataAdapter(queryString, connection);

DataSet customers = new DataSet();
adapter.Fill(customers, "myTable");

Hope this gets you going. All the best.

Answer 4

如果您指的是DbConnection类（位于System.Data.Common命名空间中），则在C＃程序中使用它的一种方法如下：

string CnnStr = "Data Source=local;Initial Catalog=dbTest;User Id=sa;pwd=1";
DbConnection cnn = new SqlConnection(CnnStr);
cnn.Open();

如何使用csharp制作和使用db连接类？

4 个答案: