连接到本地mysql服务器失败怎么办,连接到本地MySQL服务器时出现问题

I have problems connecting to a local MySQL database.

I made sure the server is running and i can connect to the server using the user and password from the connection string and create databases with the terminal.

I'm using visual studio community on a mac and MySQL 8.0.16.

Example:

Program.cs

using System;

using System.Collections.Generic;

using System.Linq;

using System.Threading.Tasks;

namespace ReadSQL

{

class Program

{

static void Main(string[] args)

{

DataAccess dataAccess = new DataAccess();

dataAccess.GetTask();

}

}

}

DataAccess.cs

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using Dapper;

using System.Data;

namespace ReadSQL

{

public class DataAccess

{

public List GetTask()

{

using (IDbConnection connection = new System.Data.SqlClient.SqlConnection(Helper.CnnVal("workloadDB")))

{

var output = connection.Query($"select * from task where id=1").ToList(); //exception thrown here

Console.WriteLine(output);

}

}

}

}

Helper.cs

using System;

using System.Collections.Generic;

using System.Configuration;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace ReadSQL

{

public static class Helper

{

public static string CnnVal(string name)

{

return ConfigurationManager.ConnectionStrings[name].ConnectionString;

}

}

}

Task.cs

using System;

namespace ReadSQL

{

public class Task

{

int id { get; set; }

string name { get; set; }

}

}

App.config

I expect the variable output to contain the first row of my table, but instead i get the error message:

System.Data.SqlClient.SqlException

A network-related or instance-specific error occurred while

establishing a connection to sql server. The server was not found or

was not accessible. Verify that the instance name is correct and that

SQL Server is configured to allow remote connections.

I don't know why i cannot establish the connection, because the MySQL Server is definitely running and the connection string should be correct (also tried: trusted_connection=true;).

Thanks in Advance!

解决方案

You cannot use the SqlConnection class to connect to MySQL. Instead, install MySqlConnector from NuGet, then use:

using (IDbConnection connection = new MySqlConnection(Helper.CnnVal("workloadDB")))

{

var output = connection.Query($"select * from task where id=1").ToList();

}

Your connection string looks like it should be compatible with MySqlConnection, but if you're using any other options you should double-check them against the list of valid connection options.