与C＃的MySQL连接

Question

I have a code written in JAVA:

String host = "jdbc:mysql://online/find";
String username = "test";
String password = "test";

And its working fine. But I want to use the same database MySQL with C#. And I am doing this:

try
{

string myConnStr = "Server=//online/find; " +
                  " Port = 3306; "+
                  " DATABASE=finder; " + 
                  " UID=test;Password=test;";

MySqlConnection MySqlConn = new MySqlConnection(myConnStr);

MySqlDataAdapter MySqlAdapter = new MySqlDataAdapter();

MySqlAdapter.SelectCommand = new MySqlCommand("Select * from finder.Customer", MySqlConn);

MySqlCommandBuilder cb = new MySqlCommandBuilder(MySqlAdapter);

MySqlConn.Open();

DataSet ds = new DataSet();

MessageBox.Show("Connected");

MySqlConn.Close();

}

But I am getting Error: " Unable to connect to any of the specified mysql hosts "

I even tried with IP address in connection string but still its not working.

I have checked these posts already:

Unable to connect to any of the specified mysql hosts. C# MySQL

unable to connect to any of the specified mysql hosts. c#

Answer 1

According to the documentation should be:

string myConnStr = 
"Database=finder;Data Source=//online/find;Port=3306;User Id=test;Password=test";

---

However for me Connection strings could be hard to remember. Its very easy to make a mistake when you write it manually. One advice is to use the server explorer to connect to your database. Then right click on your database icon > select properties ... you will see the connection string copy and paste . Voilà!

Server Explorer:

Properties:

Answer 2

尝试通过IDE服务器资源管理器->数据连接连接到服务器，并观察生成的连接字符串。

Answer 3

My first idea about the issue is "this has nothing to do with param names for username and password". You are not getting an error like:

user "null" cant login

Java and C# work on totally different foundation (Oracle vs. Microsoft) I don't know Java but I think the libraries for connecting to a remote location must be different.

I think the host URL you used is the problem:

Server=//online/find;

I use MySQL with my C# projects and I define the host value as:

• localhost or 127.0.0.1
• an IP address (xxx.xxx.xxx.xxx)
• a host url (my.dbserver.com)

here is a working MySQL connection string:

<add name="dbConnNews"
connectionString="server=xx.xx.xx.xx;database=yyyyy;User
Id=zzzzzz;Password=**********;"
providerName="MySql.Data.MySqlClient" />

Answer 4

Did you install the MySQl Connector for Microsoft Application. If yes then add a reference to MySql.dll from your C# application, then use the below connection string

string myConnStr = "server=yourMySqlServerHostorIP; port=MySqlPort;uid=username;pwd=password;initial catalog=dbname";

To download mysql connector go to http://dev.mysql.com/downloads/connector/net/ .

Let me know if it works.