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Difficulties with MySQL connection in Visual Basic 2010 Express

开发者 https://www.devze.com 2023-03-21 22:33 出处:网络
To be honest, I\'m not sure if this is an issue with my code or with settings in the database, but i\'m hoping that someone can still attempt to solve this problem with me.

To be honest, I'm not sure if this is an issue with my code or with settings in the database, but i'm hoping that someone can still attempt to solve this problem with me.

So, i've got a simple program that, for the time being, is just connecting to a simple remote mySQL database set up through WAMP and printing out the first username in the table.

The issue that i'm having i开发者_StackOverflow中文版s as follows (note - i know it says SQL Server on the first line, this is because it was hard-coded into the VB program as the first line displayed):

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)
  • The server is set up on IP address: 192.168.1.14

  • I already commented out the "Bind-Address..."

  • I created 2 database users; one set for localhost as host and the other set for % as host.

  • Username and password are very basic (they're: username//password)!

My.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

My VB script:

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

If anyone can give some insight as to what is going wrong, I will work with you from there.

Thanks.

Side-Note:

I just realized that the SQL connection works with out FTP server when running it locally on the server, but when run from a remote computer, it gives a similar issue as below, so i'm starting to lean more towards it being an issue the MySQL configuration possible?


used Neil's advice and switched SQLConnection to Odbc.OdbcConnection. it produced the following error:

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


SqlConnection only connects to MS SQL Server. To connect to MySql you need to use OdbcConnection or MySql's ado.net adapter.


You have to use the MysqlConnector. SqlConnection is for SQL Server.

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