Sql connection-string for localhost server

Question

I am newbie in this .NET and please don't mind in answering my simple question. I am trying to write a windows application, where in I am using a localhost SQLserver for database.

I need to know what is the exact connection string for my localhost, if my server name looks like as below:

Data Source=HARIHARAN-PC\SQLEXPRESS;Initial Catalog=master;Integrated Security=True

should i need to give this same as connection string, or is something wrong in this syntax.

whn i try to open my connection. I am seeing error in opening connection.

How the format of connection string should be? any one please guide me.

I tried like this :

 private void button1_Click(object sender, EventArgs e)
    {
        string str = "Data Source=HARIHARAN-PC\SQLEXPRESS;Initial Catalog=master;Integrated Security=True" ; 
        SqlConnection con = new SqlConnection(str);
        SqlCommand cmd = new SqlCommand();
        SqlDataReader r;

        cmd.CommandText = "SELECT * from Table1";
        cmd.CommandType = CommandType.Text;
        cmd.Connection = con;

        con.Open();

        r = cmd.ExecuteReader();

        con.Close();


    }

This code errors out at con.Open();

Which type of "authentication mode" you are using ?? Is it "Windows Authentication mode" or "SQL Server mode (Mixed mode)" ?? You should use **user id** and **password** in your connection string. — Krishnraj Rana, Dec 27 '13 at 07:14

score 108 · Answer 1 · answered Aug 29 '16 at 22:58

108

Using the default instance (i.e., MSSQLSERVER, use the DOT (.))

<add name="CONNECTION_STRING_NAME" connectionString="Data Source=.;Initial Catalog=DATABASE_NAME;Integrated Security=True;" />

answered Aug 29 '16 at 22:58

Robert Green MBA

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Nagaraj S · Answer 2 · 2013-12-27T07:06:50.510

21

Choose a database name in Initial Catalog

Data Source=HARIHARAN-PC\SQLEXPRESS;Initial Catalog=your database name;Integrated Security=True" ;

edited Dec 27 '13 at 07:06

answered Dec 27 '13 at 07:00

Nagaraj S

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2

[this](http://stackoverflow.com/questions/5283727/what-is-the-sql-connection-string-i-need-to-use-to-access-localhost-sqlexpress-w) post worked for me to connect to **local** using `localhost\SQLEXPRESS` – Shaiju T Dec 06 '15 at 07:05

score 16 · Answer 3 · answered Jan 02 '20 at 02:23

You can also use Dot(.) for local key i.e;

Data Source=.\SQLEXPRESS;Initial Catalog=master;Integrated Security=True

If you have the default server instance i.e. MSSQLSERVER, then just use dot for Data Source.

Data Source=.;Initial Catalog=master;Integrated Security=True

score 9 · Answer 4 · edited Dec 30 '13 at 05:49

9

Do You have Internal Connection or External Connection. If you did Internal Connection then try this:

"Data Source=.\SQLEXPRESS;AttachDbFilename="Your PAth .mdf";Integrated Security=True;User Instance=True";

edited Dec 30 '13 at 05:49

Yick Leung

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answered Dec 27 '13 at 07:05

Akil M Belim

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Ajay · Answer 5 · 2013-12-27T11:38:22.187

8

Try this connection string.

Data Source=HARIHARAN-PC\\SQLEXPRESS;Initial Catalog=yourDataBaseName;Integrated Security=True

See this link for more details http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection.connectionstring%28v=vs.110%29.aspx

edited Dec 27 '13 at 11:38

answered Dec 27 '13 at 07:04

Ajay

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score 8 · Answer 6 · answered Jul 25 '18 at 09:51

<add name="connstr" connectionString="Data Source=localhost;Initial Catalog=DBName;User Id=username;Password=password" providerName="System.Data.SqlClient"/>

The above also works. It ignores the username and password passed in in the connection string. I switched from an environment db to a local one, and it works fine even though my user in the connection string does not exist in this context.

score 5 · Answer 7 · answered Oct 16 '18 at 14:38

5

In .Net configuration I would use something like:

"Data Source=(localdb)\\MSSQLLocalDB;Initial Catalog=..."

This information is from https://www.connectionstrings.com/sql-server-2016/

answered Oct 16 '18 at 14:38

Jari Turkia

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Also see difference between SQL Express and SQL Server Developer Edition: https://stackoverflow.com/a/61659580/1548275 – Jari Turkia Nov 03 '22 at 15:50

score 4 · Answer 8 · edited Dec 27 '13 at 07:09

4

use this connection string :

Server=HARIHARAN-PC\SQLEXPRESS;Intial Catalog=persons;Integrated Security=True;

rename person with your database name

edited Dec 27 '13 at 07:09

Ram Singh

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answered Dec 27 '13 at 07:00

Waqar Ahmed

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we can use Database= persons as well .I do use it – Waqar Ahmed Dec 27 '13 at 07:10

score 3 · Answer 9 · answered Sep 11 '14 at 06:02

3

string str = @"Data Source=HARIHARAN-PC\SQLEXPRESS;Initial Catalog=master;Integrated Security=True" ;

answered Sep 11 '14 at 06:02

Mahmoud

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score 3 · Answer 10 · edited Jun 10 '19 at 20:17

3

public string strConnectionstring = "Data Source=(LocalDB)\\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\\DataBaseName.mdf";

edited Jun 10 '19 at 20:17

StealthRT

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answered Apr 08 '19 at 04:00

Aung Kyaw Nyunt

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score 2 · Answer 11 · answered Dec 27 '13 at 07:43

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string str = "Data Source=HARIHARAN-PC\\SQLEXPRESS;Initial Catalog=master;Integrated Security=True" ;

answered Dec 27 '13 at 07:43

priyana_.net

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score 1 · Answer 12 · answered Dec 27 '13 at 07:08

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When using SQL Express, you need to specify \SQLExpress instance in your connection string:

string str = "Data Source=HARIHARAN-PC\\SQLEXPRESS;Initial Catalog=master;Integrated Security=True" ;

answered Dec 27 '13 at 07:08

Vignesh Kumar A

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score 0 · Answer 13 · answered Dec 27 '13 at 07:09

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Data Source=HARIHARAN-PC\SQLEXPRESS; Initial Catalog=Your_DataBase_name; Integrated Security=true/false; User ID=your_Username;Password=your_Password;

To know more about connection string Click here

answered Dec 27 '13 at 07:09

Amarnath Balasubramanian

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Sql connection-string for localhost server

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