Database Connection issue

Bineesh Viswanath

11y1.6kLearn iOS Programming

Sir,

I am in a windows application project. My problem is of database connection could not be established.

Please help to solve this issue.

ConfigurationManager.ConnectionString[" "].ToString() is not working in my form. Here the screenshot:-

7 Replies

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Mageshwaran R6y ago
Hi,
Try this Code:[solved]
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;

namespace Storeprocedure
{
   public  class Common
   {

   SqlConnection sqlCon=null;
     String SqlconString=ConfigurationManager.ConnectionStrings["SqlConnectionString"].ConnectionString;
   public void Test(string firstName,string lastName,int age)
       {
          using(sqlCon=new SqlConnection(SqlconString))
           {
             sqlCon.Open();
             SqlCommand sql_cmnd = new SqlCommand("PROC_NAME", sqlCon);
             sql_cmnd.CommandType = CommandType.StoredProcedure;
             sql_cmnd.Parameters.AddWithValue("@FIRST_NAME", SqlDbType.NVarChar).Value=firstName;
             sql_cmnd.Parameters.AddWithValue("@LAST_NAME", SqlDbType.NVarChar).Value=lastName;
             sql_cmnd.Parameters.AddWithValue("@AGE", SqlDbType.Int).Value = age;
             sql_cmnd.ExecuteNonQuery();
             sqlCon.Close();
           }
        }
  }
}
Bharathi Raja8y ago
using system.data ;
Mukesh Sagar11y ago
define the connection string in the App.config file as :

Now with in the code , include the namespaces:

System.Data.SqlClient;
System.Configuration;

Now to read the connection string :

String strCon = ConfigurationManager.AppSettings["cn"].ToString();

Then use this for creating the SqlConnection object.
Upendra Pratap Shahi11y ago
Check the configuration class is there or not.
Bineesh Viswanath11y ago
I finded out the issue. The cause for this error was of not added reference of System.Configuration.dll.

Thank you all for the help
Raja T11y ago
Hi

Please refer bellow code. It is working fine.

Form1.Cs
-----------------
using System;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
namespace DemoWindowsFormsApplication
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
try
{
string str = ConfigurationSettings.AppSettings["ConnectionString"].ToString();
SqlConnection con = new SqlConnection(str);
con.Open();
MessageBox.Show("Connection Open");
con.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}
}

App.config
--------------
Nilesh Jadav11y ago
hey there !

Check out the given below links:

https://www.connectionstrings.com/store-connection-string-in-webconfig/

http://www.c-sharpcorner.com/UploadFile/1a81c5/configuring-connection-string-in-app-config-file-during-runt/