Get Connection String from Web.config in asp.net

Question

I want to know the ways to get connection string from web.config file in asp.net.

I just only know the below way .

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;

    namespace Sherserve.DataAccessLayer
    {
        public class DBGateway
        {
            public static string conString;

            public DBGateway()
            {
                conString = ConfigurationManager.ConnectionStrings["test"].ToString();
            }
        }
    }

It should be ConfigurationManager.ConnectionStrings["test"].ConnectionString; but that's about the only proper way you got. — user447356
– user447356, Commented Sep 19, 2012 at 7:37
so whats wrong with conString = ConfigurationManager.ConnectionStrings["test"].ToString(); — Ammar Asjad
– Ammar Asjad, Commented Sep 19, 2012 at 7:43
@Mitch please see this - your comment is not really constructive to anyone. — user447356
– user447356, Commented Sep 19, 2012 at 7:44
@Ammar regarding your question - nothing utterly wrong, see my answer now I added some more information regarding this issue. — user447356
– user447356, Commented Sep 19, 2012 at 7:49
@ShadowWizard i have seen your answer... :) your answer increased my coding knowledge. — Ammar Asjad
– Ammar Asjad, Commented Sep 19, 2012 at 7:53

score 49 · Accepted Answer · 2012-09-19 07:49:03Z

49

Using the ConfigurationManager.ConnectionStrings is about the only proper way, to use it properly with sanity check you can have such code:

public DBGateway()
{
    ConnectionStringSettings mySetting = ConfigurationManager.ConnectionStrings["test"];
    if (mySetting == null || string.IsNullOrEmpty(mySetting.ConnectionString))
        throw new Exception("Fatal error: missing connecting string in web.config file");
    conString = mySetting.ConnectionString;
}

This will throw useful error in case the connection string is missing, instead of cryptic "null object" error.

Worth to mention that the ConnectionStringSettings class is overriding the ToString() method:

public override string ToString()
{
    return this.ConnectionString;
}

So it means that using ConfigurationManager.ConnectionStrings["test"].ToString() is the same like ConfigurationManager.ConnectionStrings["test"].ConnectionString however you still better perform sanity check and personally it looks cleaner to use the actual property and not depend on the class to give it.

edited Sep 19, 2012 at 7:49

answered Sep 19, 2012 at 7:41

user447356

Sign up to request clarification or add additional context in comments.

4 Comments

sam Over a year ago

where conString came from in the line conString = mySetting.ConnectionString; ??

user447356 Over a year ago

@sam static field of the class: public static string conString;, see code in the question.

Akash Preet Over a year ago

@ShadowWizard in my case the code returns null always and I have connection string in my web.config as well.

user447356 Over a year ago

@AkashPreet either you're using wrong name of the connection string, or the web.config you see isn't the web.config that actually gets loaded, e.g. several different web.config files. Otherwise there's really no way to get null.

RL89 · Accepted Answer · 2012-09-19 07:38:23Z

9

Here is the whole solution:-

string constring = System.Configuration.ConfigurationManager.ConnectionStrings["ConnectionStringName"].ConnectionString;
SqlConnection con = new SqlConnection(constring);
DataSet ds = new DataSet();
try
 {
   SqlDataAdapter dataAdapter = new SqlDataAdapter(query, con);
   SqlCommandBuilder commandBuilder = new SqlCommandBuilder(dataAdapter);
   con.Open();
   dataAdapter.Fill(ds, "table");
   return ds;
 }
 catch (Exception ex)
  {
  }
    finally
    {
        if (con.State == System.Data.ConnectionState.Open)
            con.Close();
    }

This is how you can fetch records from database into datatable.

Hope this is what you were looking for.

answered Sep 19, 2012 at 7:38

RL89

1,9165 gold badges23 silver badges40 bronze badges

1 Comment

Ammar Asjad Over a year ago

i only want ways to get connection string.

K.M. · Accepted Answer · 2018-12-05 11:04:04Z

2

Try

 string ConString = System.Configuration.ConfigurationManager.ConnectionStrings[ConfigurationManager.ConnectionStrings.Count -1].ConnectionString;

answered Dec 5, 2018 at 11:04

K.M.

315 bronze badges

Comments

mRizvandi · Accepted Answer · 2014-02-26 18:17:26Z

I have a method on my WebAssistant Class. i have a key on appSettings that contain my WebAppName, check the below line:

<add key="DOMAIN_NAME" value="mRizvandi.com"/>

and my connection name alwyas has "DomainName"+"DBConnectionString" template such as:

<add name="mRizvandiDBConnectionString" connectionString=...

Ok, everything are ready to get connectionstring without pass any string.

    public static string GetDBConnectionString()
    {
        string retValue = "";
        string domainUrl = "";
        string connectionKey = "";
        string dbConnectionString = "";

        domainUrl = GetDomainUrl();
        connectionKey = domainUrl.Substring(0, domainUrl.IndexOf(".")) + "DBConnectionString";
        dbConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings[connectionKey].ToString();
        retValue = dbConnectionString;

        return retValue;
    }

I hope would be helpful.

CREM · Accepted Answer · 2016-08-02 17:48:23Z

0

Following code works for me. I've added the exception in case connectionString not founded in web.config

web.config:

 <configuration>
  <connectionStrings>
    <add name="DBConnection" connectionString="Data Source=myaddress;Initial Catalog=MyCatalog;User ID=myuser;Password=pass;Encrypt=True;TrustServerCertificate=False"
         providerName="System.Data.SqlClient" />
  </connectionStrings>
</configuration>

In my connection class:

static internal string GetSqlConnectionString(){

try {
    ConnectionStringSettings mySetting = ConfigurationManager.ConnectionStrings("DataBaseConnection");
    if (mySetting == null)
        throw new Exception("Database connection settings have not been set in Web.config file");

    return mySetting.ConnectionString;

} catch (Exception ex) {
    throw;
}}

edited Aug 2, 2016 at 17:48

answered Aug 2, 2016 at 15:48

CREM

2,0211 gold badge28 silver badges36 bronze badges

1 Comment

help-info.de Over a year ago

This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post - you can always comment on your own posts, and once you have sufficient reputation you will be able to comment on any post.

Collectives™ on Stack Overflow

Get Connection String from Web.config in asp.net

5 Answers 5

4 Comments

1 Comment

Comments

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

4 Comments

1 Comment

Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related