Visual Basic 2010 Express 中 MySQL 连接的困难

Question

说实话，我不确定这是我的代码问题还是数据库中的设置问题，但我希望有人仍然可以尝试与我一起解决这个问题。

所以，我有一个简单的程序，目前它只是连接到一个通过 WAMP 设置的简单远程 mySQL 数据库并打印出表中的第一个用户名。

我遇到的问题如下（注意 - 我知道它在第一行显示 SQL Server，这是因为它在第一行显示时被硬编码到 VB 程序中）：

Error while connecting to SQL Server.

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 SQLServer is configured to allow remote connections. 

(provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

• 服务器设置在 IP 地址：192.168.1.14

• 我已经注释掉了“绑定地址...”

• 我创建了 2 个数据库用户；一组设置为 localhost 作为主机，另一组设置为 % 作为主机。

• 用户名和密码非常基础（分别是：用户名//密码）！

我的.ini：

# Example MySQL config file for medium systems.
#
# This is for a system with little memory (32M - 64M) where MySQL plays
# an important part, or systems up to 128M where MySQL is used together with
# other programs (such as a web server)
#
# You can copy this file to
# /etc/my.cnf to set global options,
# mysql-data-dir/my.cnf to set server-specific options (in this
# installation this directory is C:\mysql\data) or
# ~/.my.cnf to set user-specific options.
#
# In this file, you can use all long options that a program supports.
# If you want to know which options a program supports, run the program
# with the "--help" option.

# The following options will be passed to all MySQL clients
[client]
#password   = your_password
port        = 3306
socket      = /tmp/mysql.sock

# Here follows entries for some specific programs

# The MySQL server
[wampmysqld]
port        = 3306
socket      = /tmp/mysql.sock
key_buffer = 16M
max_allowed_packet = 1M
table_cache = 64
sort_buffer_size = 512K
net_buffer_length = 8K
read_buffer_size = 256K
read_rnd_buffer_size = 512K
myisam_sort_buffer_size = 8M
basedir=c:/wamp/bin/mysql/mysql5.5.8
log-error=c:/wamp/logs/mysql.log
datadir=c:/wamp/bin/mysql/mysql5.5.8/data
#bind-address=127.0.0.1

# Don't listen on a TCP/IP port at all. This can be a security enhancement,
# if all processes that need to connect to mysqld run on the same host.
# All interaction with mysqld must be made via Unix sockets or named pipes.
# Note that using this option without enabling named pipes on Windows
# (via the "enable-named-pipe" option) will render mysqld useless!
# 
#skip-networking

# Disable Federated by default
skip-federated

# Replication Master Server (default)
# binary logging is required for replication
log-bin=mysql-bin

# binary logging format - mixed recommended
binlog_format=mixed

# required unique id between 1 and 2^32 - 1
# defaults to 1 if master-host is not set
# but will not function as a master if omitted
server-id   = 1

# Replication Slave (comment out master section to use this)
#
# To configure this host as a replication slave, you can choose between
# two methods :
#
# 1) Use the CHANGE MASTER TO command (fully described in our manual) -
#    the syntax is:
#
#    CHANGE MASTER TO MASTER_HOST=<host>, MASTER_PORT=<port>,
#    MASTER_USER=<user>, MASTER_PASSWORD=<password> ;
#
#    where you replace <host>, <user>, <password> by quoted strings and
#    <port> by the master's port number (3306 by default).
#
#    Example:
#
#    CHANGE MASTER TO MASTER_HOST='125.564.12.1', MASTER_PORT=3306,
#    MASTER_USER='joe', MASTER_PASSWORD='secret';
#
# OR
#
# 2) Set the variables below. However, in case you choose this method, then
#    start replication for the first time (even unsuccessfully, for example
#    if you mistyped the password in master-password and the slave fails to
#    connect), the slave will create a master.info file, and any later
#    change in this file to the variables' values below will be ignored and
#    overridden by the content of the master.info file, unless you shutdown
#    the slave server, delete master.info and restart the slaver server.
#    For that reason, you may want to leave the lines below untouched
#    (commented) and instead use CHANGE MASTER TO (see above)
#
# required unique id between 2 and 2^32 - 1
# (and different from the master)
# defaults to 2 if master-host is set
# but will not function as a slave if omitted
#server-id       = 2
#
# The replication master for this slave - required
#master-host     =   <hostname>
#
# The username the slave will use for authentication when connecting
# to the master - required
#master-user     =   <username>
#
# The password the slave will authenticate with when connecting to
# the master - required
#master-password =   <password>
#
# The port the master is listening on.
# optional - defaults to 3306
#master-port     =  <port>
#
# binary logging - not required for slaves, but recommended
#log-bin=mysql-bin

# Point the following paths to different dedicated disks
#tmpdir     = /tmp/     
#log-update     = /path-to-dedicated-directory/hostname

# Uncomment the following if you are using InnoDB tables
#innodb_data_home_dir = C:\mysql\data/
#innodb_data_file_path = ibdata1:10M:autoextend
#innodb_log_group_home_dir = C:\mysql\data/
#innodb_log_arch_dir = C:\mysql\data/
# You can set .._buffer_pool_size up to 50 - 80 %
# of RAM but beware of setting memory usage too high
#innodb_buffer_pool_size = 16M
#innodb_additional_mem_pool_size = 2M
# Set .._log_file_size to 25 % of buffer pool size
#innodb_log_file_size = 5M
#innodb_log_buffer_size = 8M
#innodb_flush_log_at_trx_commit = 1
#innodb_lock_wait_timeout = 50

[mysqldump]
quick
max_allowed_packet = 16M

[mysql]
no-auto-rehash
# Remove the next comment character if you are not familiar with SQL
#safe-updates

[isamchk]
key_buffer = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M

[myisamchk]
key_buffer = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M

[mysqlhotcopy]
interactive-timeout

[mysqld]
port=3306

---

我的 VB 脚本：

Imports System.IO
Imports System.Data
Imports System.Data.SqlClient

Module SQLcon1

    'Dim connect As New SqlConnection

    Sub Main()
        Dim con As String = "server=192.168.1.14;uid=username;pwd=password;database=apache_test;"
        'Alt method         "Data Source=192.168.1.14;Initial Catalog=apache_test;Persist Security Info=True;User ID=username;Password=password"
        Dim connect As New SqlConnection(con)
        Try
            connect.Open()
            Dim command As New SqlCommand("SELECT userid from TABLE2 limit 1", connect)
        Catch ex As Exception
            Console.WriteLine("Error while connecting to SQL Server." & ex.Message)
            connect.Close() 'Whether there is error or not. Close the connection.
        End Try
        Console.WriteLine("Press Enter to continue")
        Console.ReadLine()
    End Sub
End Module

---

如果有人可以就问题所在提供一些见解，我会从那里与您合作。

谢谢。

Side-Note:

我刚刚意识到，当在服务器上本地运行 SQL 连接时，它与 FTP 服务器一起工作，但是当从远程计算机运行时，它给出了类似的问题，所以我开始更倾向于它MySQL 配置有问题吗？

---

使用 Neil 的建议并将 SQLConnection 切换为 Odbc.OdbcConnection。它产生了以下错误：

ERROR [IM002] [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified

Answer 1

SqlConnection 仅连接到 MS SQL Server。要连接到 MySql，您需要使用 OdbcConnection 或 MySql 的 ado.net 适配器。

Answer 2

您必须使用MysqlConnector。 SqlConnection 用于 SQL Server。