I am trying to read a table from a Wampserver using this, but I get an error message "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. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)"
When I ping localhost all the pings are received. Is this code correct?
private void button5_Click(object sender, EventArgs e)
{
SqlConnection myConnection = new SqlConnection("user id=root;" +
"password=pass;server=localhost;" +
"database=database; " +
"connection timeout=10");
string query = "select * from table";
SqlCommand cmd = new SqlCommand(query, myConnection);
myConnection.Open(); // the error
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(tabelsql);
myConnection.Close();
da.Dispose();
}
If you're using a WampServer than that means you're using MySQL, right?
MySQL and SQL Server are not the same. SQLConnection, SQLCommand and SQLDataAdapter are used to connect to SQL Server (the RDBMS from Microsoft), not MySQL.
To access a MySQL database from .NET you can use the MySQL Connector.
SqlCommand and SqlDataAdapter are part of the MS SQL ADO.NET native client and can only be used for MS Sql Server. WAMP appears to include MySql. For that, you'll likely want to use the MySql ADO.NET driver found here. And this article provides some sample code for reading MySql data utilizing a DataReader.
To Read a single table from MySql database which is in wamp server.
If wamp-server is in localhost then,
Add reference ..
using MySql.Data.MySqlClient;
And after this..
write below public partial class this connection query..
MySqlConnection cn = new
MySqlConnection
("server=localhost;database=database;userid=root;password=;charsetutf8;");
write this GetData() in your form load event or below InitializeComponent...
private void GetData()
{
cn.Open();
MySqlDataAdapter adp = new MySqlDataAdapter("SELECT * from
tablename", cn);
DataTable dt = new DataTable();
adp.Fill(dt);
dataGridViewName.DataSource = dt;
adp.Dispose();
cn.Close();
}
Related
Is self signed certificate disrupting connection to mysql?
I already give action crud in data and grant access to administration.
but the connection still got error.
Unable to connect to any of the specified MySQL hosts
my team connection like this:
Catalog=devbaf;User Id=userclient;password=client123
connection code:
try
{
string constring = "SERVER=123.45.678.9;DATABASE=devbaf;User Id=backendsystem;PASSWORD=1q2w3e4r5t;";
using (MySqlConnection con = new MySqlConnection(constring))
{
using (MySqlCommand cmd = new MySqlCommand("SELECT * FROM users"))
{
using (MySqlDataAdapter sda = new MySqlDataAdapter())
{
cmd.Connection = con;
sda.SelectCommand = cmd;
using (DataTable dt = new DataTable())
{
sda.Fill(dt);
gvtest.DataSource = dt;
gvtest.DataBind();
}
}
}
}
}
catch (Exception e)
{
Response.Write(e.Message.ToString());
}
explanation problem:
I make a database in local server, so my friend can access to it to insert data. but when he make a connection script it wont connect to my database but can connect to server. He already tries to move some file to the server and it works,but the connection to database wont connect. i don't have an experience for this coz im php programmer not c# programmer. hope my explanation is clear.
I have found your error message like trying to connect the host but in your connection string is missing the MySQL server name or host address. I hope if you add the MySQL hostname or server address to your connection. it will fix your issue.
you can try this
string connectionString ="SERVER=servername; DATABASE=databasename; User Id=userid; PASSWORD=password;";
First off, i know this has been asked a million times but i just cannot figure it out what is going wrong.
I have made a local database using Microsoft Management Studio and i want to connect to it through C#. Heres my code:
string connStr = "Server=MSSQLSERVER;Database=UrenRegi;IntegratedSecurity=yes;Uid=auth_windows;";
MySqlConnection conn = new MySqlConnection(connStr);
conn.Open();
MySqlCommand cmd = new MySqlCommand("SELECT * From Users", conn);
MySqlDataAdapter adp = new MySqlDataAdapter(cmd);
DataSet ds = new DataSet();
adp.Fill(ds, "LoadDataBinding");
dataGrid.DataContext = ds;
conn.Close();
The error: Additional information: Unable to connect to any of the specified MySQL hosts.
Im using windows authentication because i know for sure that it is working.
Microsoft SQL Server is not MySQL. Use SqlConnection instead of MySqlConnection (same for all other classes).
I have added a SQL Server .mdf database file to my C# application, but when I try to connect with this code, the program causes a connection error.
CODE:
DataSet data;
string con = "Data Source=dbinterno.mdf;";
string queryString = "Select * FROM Dati";
try
{
using (SqlConnection connection = new SqlConnection(con))
{
connection.Open();
SqlDataAdapter adapter = new SqlDataAdapter();
SqlCommand command = new SqlCommand(queryString, connection);
command.ExecuteNonQuery();
data = new DataSet();
adapter.Fill(data);
MessageBox.Show(data.ToString());
connection.Close();
}
}
catch
{
MessageBox.Show("\n Problemi di connessione al database");
}
The error is:
ERROR IMAGE
Here are a couple observations:
Your connection string will need to be modified. Try using
string con = "Server=myServerAddress;Database=myDataBase;Trusted_Connection=True;";
using Windows Authentication or this:
string con = "Server=myServerAddress;Database=myDataBase;User Id=myUsername;
Password=myPassword;"; using standard security, Source: connectionstrings.com. This should be managed some other way than in code as well. Desktop applications can be de-compiled, and if the password changes, you would need a rebuild. In a ASP.NET application, Microsoft advises to use a web.config file or in the windows registry using a custom subkey.
You will want to use ExecuteReader() for a SELECT statement as ExecuteNonQuery() will not return a result set. See this answer that describes the differences in the types of SQL Server methods
you don't need connection.Close();, the using statement will handle that.
I'm connecting my windows form application to SQL server but I get this error "SqlException was unhandled" when I start the program.
Here is my code:
void ShowEmployees()
{
using (SqlConnection Connect = new SqlConnection("Data Source=(local);" + "Database='SanMarDryCleaners';" + "Integrated Security=SSPI;"))
{
string strEmployees = "SELECT * FROM employees;";
SqlCommand cmdEmployees = new SqlCommand(strEmployees, Connect);
SqlDataAdapter daEmployees = new SqlDataAdapter();
daEmployees.SelectCommand = cmdEmployees;
DataSet dsEmployees = new DataSet("EmployeesSet");
daEmployees.Fill(dsEmployees);
Connect.Open();
dgvEmployees.DataSource = dsEmployees;
dgvEmployees.DataMember = dsEmployees.Tables[0].TableName;
}
}
Here is the screenshot:
The error suggest that it can't find the SQL Server. And that makes sense because you are using a SqlConnection class which is for Microsoft SQL Server only. You have to use MySQL libary.
Download it from this site:
http://dev.mysql.com/downloads/connector/net/
The error points to a problem while connecting to the server.
A SqlConnection is for SQL-Servers. Use a library specific to MySQL and a MySqlConnection.
See:
Connector/Net Installation
MySQL Connector/Net connection strings
I can't find the mistake in my code below.When I use SQLDataSource to connect my database,there's no error.However,if I try to write the custom code to connect the database using the same connection string SQLDataSource uses,I encounter this error:
(provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)
I suppose there's no mistake in my code,but in the configuration settings of SQL 2008 Express.
Thanks in advance...
SqlConnection sqlcon = new SqlConnection();
sqlcon.ConnectionString = "Data Source=ERHANEMREEROGLU/SQLEXPRESS;Initial Catalog=KET;Integrated Security=True";
sqlcon.Open();
SqlCommand sqlcmd = new SqlCommand();
sqlcmd.Connection=sqlcon;
sqlcmd.CommandText = "SELECT * FROM Login";
sqlcmd.CommandType = CommandType.Text;
sqlcmd.ExecuteNonQuery();
sqlcon.Close();
Shouldn't this read:
sqlcon.ConnectionString = "Data Source=ERHANEMREEROGLU\\SQLEXPRESS;Initial Catalog=KET;Integrated Security=True";
There problem is in the statement in sqlcmd.ExecuteNonQuery();
SqlDataAdapter adapter = new SqlDataAdapter("SELECT * FROM Login", sqlcmd))
DataTable t = new DataTable();
adapter.Fill(t);
Actualy you are executing a query and you need either SqlDataReader or SqlDataAdapter here.
Try to check if your SQL server allows remote connections, you can set that in the sql server configuration manager
and then enable the remote TCP connection
You should change your line from:
sqlcmd.ExecuteNonQuery();
to:
SqlDataReader dr = sqlcmd.ExecuteReader();
If you are using Windows Authentication on your SQL database you may need to change the Integrated Security to SSPI? Although I'm not overly sure. - edit reading some information about this and SSPI is equivalent to True, so see suggestions below instead.
sqlcon.ConnectionString = "Data Source=ERHANEMREEROGLU/SQLEXPRESS;Initial Catalog=KET;Integrated Security=SSPI";
But as John Blade said you may also need to check in the Configuration Manager that it accepts remote connections.
Also make sure you've added the Windows user to the database. You can do this by using the SQL Mangement Studio Tools.
You are executing ExecuteNonQuery(); which is for Insert/update/delete statements. You may fill a DataReader using ExecuteReader or a dataset/datatable using SQLDataAdapter.
SqlDataReader reader = sqlcmd.ExecuteReader();
while (reader.Read())
{
Console.WriteLine(String.Format("{0}", reader[0]));
}
You can try:
using (SqlConnection sqlcon = new SqlConnection(
"Data Source=ERHANEMREEROGLU\\SQLEXPRESS;Initial Catalog=KET;Integrated Security=True"))
{
sqlcon.Open();
using (SqlDataAdapter a = new SqlDataAdapter("SELECT * FROM Login", sqlcon ))
{
DataTable t = new DataTable();
a.Fill(t);
}
}