使用dot Net Windows Apps远程连接MySQL数据库 [英] Connect MySQL Database Remotely with dot Net Windows Apps

问题描述

为商店的零售管理开发窗口应用程序。数据库安装在服务器中，但应用程序安装在不同的计算机上，无法连接数据库。

Plz告诉我确切的代码......

i我正在尝试..

  string  strCon =   server = 198.168.1.162; Database = inventory; UserID = root; Password = root; 
 MySqlConnection con =  new  MySqlConnection（GlobalConectionClass.FnConnection（））; 
  private   void  FillDdl（）
 {
 尝试 
 {
 字符串 QrySuppType =  按供应商类型选择*按类型asc; 
  //   MySqlDataAdapter adpQrySuppType = new MySqlDataAdapter（QrySuppType，con）;  
 < span class =code-comment> //   DataSet dsQrySuppType = new DataSet（）;  
 MySqlCommand cmd1 =  new  MySqlCommand（QrySuppType，con）; 
 con.Open（）; 
 MySqlDataReader dr1 = cmd1.ExecuteReader（）; 
  while （dr1.Read（））
 {
 ddlSuppType.Items.Add（dr1 [  type]。ToString（））; 
 ddlSearchST.Items.Add（dr1 [  type]。ToString（））; 
 ddlRemoveSupType.Items.Add（dr1 [  type]。ToString（））; 
} 
 dr1.Close（）; 
} 
  catch  
 {
} 
  finally  
 {
 con.Close（）; 
} 
} 

解决方案

在服务器系统上的mysql服务器中创建新用户并允许访问库存数据库到该用户，然后更改代码中的用户名和密码。无需更改代码

此代码由VB.NET 2008& MySQL



步骤1



使用以下代码创建一个模块。

  Imports  MySql.Data.MySqlClient 
 模块 mod_databaseconnection 
 
 公共 cn 作为 MySqlConnection 
 公共 cmd 作为 新 MySqlCommand 
  Public  dr  As  MySqlDataReader 
  Public   Sub  open_clienconnection（）
 尝试 
 cn = 新 MySqlConnection 
 cn.ConnectionString =   server = 192.168.232.11 ;用户ID = r oot; password = 4; Persist Security Info = True; database = test 
 cn.Open（）
 cmd.Connection = cn 
  Catch  ex  As 异常
 MessageBox.Show（ 发生意外的数据库连接错误。& vbCrLf& ex.Message， 注意，MessageBoxButtons.OK，MessageBoxIcon。错误）
 
 结束 尝试 
 结束  Sub  
 
 结束 模块 

第2步



在每个sql查询中你都会执行确保调用open_clienconnection（）





代码将以某种方式看起来像这样

 open_clienconnection（）
 cmd.CommandText =    select * from MyTable 
 dr = cmd.ExecuteReader 
 dr.Read（）
 

如果有效，请告诉我。

您好，



请在MySQL上启用TCP / IP网络。默认情况下，在安装MySQL服务器时未启用此选项。还要确保从远程计算机授予mysql数据库用户访问权限。您可以通过发出以下命令来执行此操作。默认情况下，root不允许从localhost以外的机器连接，即安装MySQL服务器的机器。

  GRANT  priv_type  ON  db_name。*  TO  user_name @ remote_host 

注释 -

• 此处小写的值表示您需要根据用户数据库和用户更改的值
• 有关 GRANT 命令的更多帮助，请查看MySQL文档

问候，

Developing a Window apps for Retail Management of a Store. The database is installed in a Server but application is installed to different Computers and Unable to connect Database.
Plz tell me exact code ....
i am trying..

string strCon = "server =198.168.1.162 ;Database=inventory;UserID=root;Password=root";
 MySqlConnection con = new MySqlConnection(GlobalConectionClass.FnConnection());
private void FillDdl()
        {
            try
            {                
                string QrySuppType = "Select * from supplier_type order by type asc";
                //MySqlDataAdapter adpQrySuppType = new MySqlDataAdapter(QrySuppType, con);
                //DataSet dsQrySuppType = new DataSet();
                MySqlCommand cmd1 = new MySqlCommand(QrySuppType,con);
                con.Open();
                MySqlDataReader dr1 = cmd1.ExecuteReader();
                while (dr1.Read())
                {
                    ddlSuppType.Items.Add(dr1["type"].ToString());
                    ddlSearchST.Items.Add(dr1["type"].ToString());
                    ddlRemoveSupType.Items.Add(dr1["type"].ToString());
                }
                dr1.Close();
            }
            catch
            {
            }
            finally
            {
                con.Close();
            }
        }

解决方案

create new user in mysql server on server system and allow the access to the inventory database to that user and then change the username and password in your code. no need to change the code

This code is made out of VB.NET 2008 & MySQL

Step 1

Create a Module with the following code.

Imports MySql.Data.MySqlClient
Module mod_databaseconnection

    Public cn As MySqlConnection
    Public cmd As New MySqlCommand
    Public dr As MySqlDataReader
    Public Sub open_clienconnection()
        Try
            cn = New MySqlConnection
            cn.ConnectionString = "server=192.168.232.11;User Id=root;password=4;Persist Security Info=True;database=test"
            cn.Open()
            cmd.Connection = cn
        Catch ex As Exception
            MessageBox.Show("An unexpected database connection error occured." & vbCrLf & ex.Message, "Attention", MessageBoxButtons.OK, MessageBoxIcon.Error)
          
        End Try
    End Sub

End Module

Step 2

In every sql query you will execute make sure to call "open_clienconnection()"


Code will somehow look like this

open_clienconnection()
            cmd.CommandText = "select * from MyTable"
            dr = cmd.ExecuteReader
            dr.Read()

Let me know if this works.

Hello,

Please enable TCP/IP networking on the MySQL. By default this option is not enabled while you install the MySQL Server. Also make sure that the mysql database user is granted access from the remote machine. You can do this by issuing following command. By default root is not allowed to connect from machine other than the localhost i.e. the machine on which MySQL server is installed.

GRANT priv_type ON db_name.* TO user_name@remote_host

Notes -

• Here values in small case denotes the values you will need to change with respect to user database and user
• For more help on GRANT command have a look at MySQL Documentation

Regards,

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