Getting Error while connecting the database

Hey Rajesh,

If you are getting same error after Correcting the CODE then don't panic its not error about you code , this error can occur if SqlServer.exe is not running.

if the process SQLServer.exe is not running then SQL SERVER Gives the error that you face currently.

SQLServer.exe is used as instance of SQL Server.

you can Run this from SQL Server Configuration Manager Wizard.(use above path)






Then check whether Sql Server Browser is running or not , if not then turn it on.




Figure Source : Internet

I am not sure what your question is.

In the first connection string (the one that does not work) you have "database=MyWorkers.mdf". There is no qualification for the filename so it looks in the default location for the database. In your second connection string (the one that does work) you have "AttachDBFilename=C:\\MyWorkers.mdf" so it knows exactly where the file is at. Also note that the root of your C: is definitely not where it would expect (look for) the database.

Also note that in your first connection string you use "server=.//SQLEXPRESS" (with forward slashes) and in the other one you use "DataSource=.\\SQLEXPRESS" (with backslahes). Since the error message says that the "server was not found" the error seems to be that ".//SQLEXPRESS" is invalid; I assume that the problem is the forward slashes.

Hi Rajesh,

Create an app.config file.
First in the app.config file there you declare the connection string as below.




 
   
 



Then call the key name in your application as below
string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"];


Iam giving a example how to show records in datagridview using this connection.


using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"];
        SqlCommand com;
        SqlDataAdapter sqlda;
        DataSet ds;
        string str;
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection(ConnectionString);
            con.Open();
            str = "select * from employee";
            com = new SqlCommand(str, con);
            sqlda = new SqlDataAdapter(com);
            ds = new DataSet();
            sqlda.Fill(ds, "employee");
            dataGridView1.DataSource = ds;
            dataGridView1.DataMember = "employee";
            con.Close();
        }
    }
}

Please Run the attachments also for the output.



Thanks
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Your link provide me very good knowledge but i have read the above code from many books all the books gives same code but this code doesn't work so i want to know what actually wrong with that code. Plzzzzzzzzzzz help me.

 Check this article.. 

 How to: Generate or find Connection String from Visual Studio