c# - 通过 C# 连接到 MySQL 服务器

Question

这是我的代码，用于连接到 MySQL 服务器并获取一些信息:

using System;
using System.Collections.Generic;
using System.Text;
using System.Data.SqlClient;

namespace test_MLDropCopy
{
    class Program
    {
        static void Main(string[] args)
        {
            string connectionString = "server=xxxxx;uid=xxxxx;pwd=xxxxx";

            SqlConnection mySqlConnection = new SqlConnection(connectionString);

            string selectString = "select Symbol from today_positions.all_rttp where ServiceName like 'ML%' and ID = 137800";

            SqlCommand mySqlCommand = mySqlConnection.CreateCommand();

            mySqlConnection.Open(); 

            mySqlCommand.CommandText = selectString;

            SqlDataReader myReader = null;

            myReader = mySqlCommand.ExecuteReader();

            string Symbol = myReader["Symbol"].ToString();

            Console.WriteLine(Symbol);

            mySqlConnection.Close();


        }
    }
}

但是，这是我遇到的错误:

Unhandled Exception: System.Data.SqlClient.SqlException: A network-related or in
stance-specific error occurred while establishing a connection to SQL Server. Th
e server was not found or was not accessible. Verify that the instance name is c
orrect and that SQL Server is configured to allow remote connections. (provider:
 Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

我已经仔细检查了我使用的登录凭据。是我的代码有问题，还是数据库端的问题(离线、权限不足等)？

Answer 1

您正在尝试连接到 Microsoft SQL Server。

使用 Connector/Net文件代替。例如。来自 intro tutorial

string connStr = "server=localhost;user=root;database=world;port=3306;password=******;";
MySqlConnection conn = new MySqlConnection(connStr);

请注意，由于 MySQL 和 SQL Server 都实现了 ADO.NET 接口(interface)，因此您可以输入 IDbConnection作为 conn 的类型(同样的原则适用于其他变量)。