Connection strings for SQL Server 2012

.NET Framework Data Provider for SQL Server

Type .NET Framework Class Library
 Usage System.Data.SqlClient.SqlConnection
 Manufacturer Microsoft
More info and class library downloads

Set example values

Standard Security

    
Server=myServerAddress;Database=myDataBase;User Id=myUsername;Password=myPassword;
 
 

Trusted Connection

    
Server=myServerAddress;Database=myDataBase;Trusted_Connection=True;
 
 

Connection to a SQL Server instance

The server/instance name syntax used in the server option is the same for all SQL Server connection strings.

    
Server=myServerName\myInstanceName;Database=myDataBase;User Id=myUsername;
Password=myPassword;
 
 

Trusted Connection from a CE device

A Windows CE device is most often not authenticated and logged in to a domain but it is possible to use SSPI or trusted connection and authentication from a CE device using this connection string.

    
Data Source=myServerAddress;Initial Catalog=myDataBase;Integrated Security=SSPI;
User ID=myDomain\myUsername;Password=myPassword;

Note that this will only work on a CE device.

 
 

Connect via an IP address

    
Data Source=190.190.200.100,1433;Network Library=DBMSSOCN;Initial Catalog=myDataBase;
User ID=myUsername;Password=myPassword;

DBMSSOCN=TCP/IP is how to use TCP/IP instead of Named Pipes. At the end of the Data Source is the port to use. 1433 is the default port for SQL Server. Read more here.

 
 

Enable MARS

    
Server=myServerAddress;Database=myDataBase;Trusted_Connection=True;
MultipleActiveResultSets=true;
 
 

Attach a database file on connect to a local SQL Server Express instance

    
Server=.\SQLExpress;AttachDbFilename=c:\asd\qwe\mydbfile.mdf;Database=dbname;
Trusted_Connection=Yes;

Why is the Database parameter needed? If the named database have already been attached, SQL Server does not reattach it. It uses the attached database as the default for the connection.

 
 

Attach a database file, located in the data directory, on connect to a local SQL Server Express instance

    
Server=.\SQLExpress;AttachDbFilename=|DataDirectory|mydbfile.mdf;Database=dbname;
Trusted_Connection=Yes;

Why is the Database parameter needed? If the named database have already been attached, SQL Server does not reattach it. It uses the attached database as the default for the connection.

 
 

User Instance on local SQL Server Express

The User Instance feature is deprecated with SQL Server 2012, use the SQL Server Express LocalDB feature instead.

 
 

LocalDB automatic instance

    
Server=(localdb)\v11.0;Integrated Security=true;

The first connection to LocalDB will create and start the instance, this takes some time and might cause a connection timeout failure. If this happens, wait a bit and connect again.

 
 

LocalDB automatic instance with specific data file

    
Server=(localdb)\v11.0;Integrated Security=true;AttachDbFileName=C:\MyFolder\MyData.mdf;
 
 

LocalDB named instance

To create a named instance, use the SqlLocalDB.exe program. Example SqlLocalDB.exe create MyInstance and SqlLocalDB.exe start MyInstance

    
Server=(localdb)\MyInstance;Integrated Security=true;
 
 

LocalDB named instance via the named pipes pipe name

The Server=(localdb) syntax is not supported by .NET framework versions before 4.0.2. However the named pipes connection will work to connect pre 4.0.2 applications to LocalDB instances.

    
Server=np:\\.\pipe\LOCALDB#F365A78E\tsql\query;

Executing SqlLocalDB.exe info MyInstance will get you (along with other info) the instance pipe name such as "np:\\.\pipe\LOCALDB#F365A78E\tsql\query".

 
 

LocalDB shared instance

Both automatic and named instances of LocalDB can be shared.

    
Server=(localdb)\.\MyInstanceShare;Integrated Security=true;

Use SqlLocalDB.exe to share or unshare an instance. For example execute SqlLocalDB.exe share "MyInstance" "MyInstanceShare" to share an instance.

 
 

Database mirroring

If you connect with ADO.NET or the SQL Native Client to a database that is being mirrored, your application can take advantage of the drivers ability to automatically redirect connections when a database mirroring failover occurs. You must specify the initial principal server and database in the connection string and the failover partner server.

    
Data Source=myServerAddress;Failover Partner=myMirrorServerAddress;
Initial Catalog=myDataBase;Integrated Security=True;

There is ofcourse many other ways to write the connection string using database mirroring, this is just one example pointing out the failover functionality. You can combine this with the other connection strings options available.

 
 

Asynchronous processing

A connection to SQL Server that allows for the issuing of async requests through ADO.NET objects.

    
Server=myServerAddress;Database=myDataBase;Integrated Security=True;
Asynchronous Processing=True;

See also the List of all SqlConnection connection string properties

 
 

SQL Server Native Client 11.0 OLE DB Provider

Type OLE DB Provider
 Usage Provider=SQLNCLI11
 Manufacturer Microsoft
More info and provider downloads

Set example values

Standard security

    
Provider=SQLNCLI11;Server=myServerAddress;Database=myDataBase;Uid=myUsername;
Pwd=myPassword;

Are you using SQL Server 2012 Express? Don't miss the server name syntax Servername\SQLEXPRESS where you substitute Servername with the name of the computer where the SQL Server 2012 Express installation resides.

When to use SQL Native Client?

 
 

Trusted connection

    
Provider=SQLNCLI11;Server=myServerAddress;Database=myDataBase;Trusted_Connection=yes;

Equivalent key-value pair: "Integrated Security=SSPI" equals "Trusted_Connection=yes"

 
 

Connecting to an SQL Server instance

The syntax of specifying the server instance in the value of the server key is the same for all connection strings for SQL Server.

    
Provider=SQLNCLI11;Server=myServerName\theInstanceName;Database=myDataBase;
Trusted_Connection=yes;
 
 

Prompt for username and password

This one is a bit tricky. First you need to set the connection object's Prompt property to adPromptAlways. Then use the connection string to connect to the database.

    
oConn.Properties("Prompt") = adPromptAlways

oConn.Open "Provider=SQLNCLI11;
Server=myServerAddress;DataBase=myDataBase;
 
 

Enable MARS

    
Provider=SQLNCLI11;Server=myServerAddress;Database=myDataBase;Trusted_Connection=yes;
MARS Connection=True;
 
 

Encrypt data sent over network

    
Provider=SQLNCLI11;Server=myServerAddress;Database=myDataBase;Trusted_Connection=yes;
Encrypt=yes;
 
 

Attach a database file on connect to a local SQL Server Express instance

    
Provider=SQLNCLI11;Server=.\SQLExpress;AttachDbFilename=c:\asd\qwe\mydbfile.mdf;
Database=dbname;Trusted_Connection=Yes;

Why is the Database parameter needed? If the named database have already been attached, SQL Server does not reattach it. It uses the attached database as the default for the connection.

 
 

Attach a database file, located in the data directory, on connect to a local SQL Server Express instance

    
Provider=SQLNCLI11;Server=.\SQLExpress;AttachDbFilename=|DataDirectory|mydbfile.mdf;
Database=dbname;Trusted_Connection=Yes;

Why is the Database parameter needed? If the named database have already been attached, SQL Server does not reattach it. It uses the attached database as the default for the connection.

 
 

Database mirroring

If you connect with ADO.NET or the SQL Native Client to a database that is being mirrored, your application can take advantage of the drivers ability to automatically redirect connections when a database mirroring failover occurs. You must specify the initial principal server and database in the connection string and the failover partner server.

    
Provider=SQLNCLI11;Data Source=myServerAddress;Failover Partner=myMirrorServerAddress;
Initial Catalog=myDataBase;Integrated Security=True;

There is ofcourse many other ways to write the connection string using database mirroring, this is just one example pointing out the failover functionality. You can combine this with the other connection strings options available.

 
 

SQL Server Native Client 11.0 ODBC Driver

Type ODBC Driver
 Usage Driver={SQL Server Native Client 11.0}
 Manufacturer Microsoft
More info and driver downloads

Set example values

Standard security

    
Driver={SQL Server Native Client 11.0};Server=myServerAddress;Database=myDataBase;
Uid=myUsername;Pwd=myPassword;

Are you using SQL Server 2012 Express? Don't miss the server name syntax Servername\SQLEXPRESS where you substitute Servername with the name of the computer where the SQL Server 2012 Express installation resides.

When to use SQL Native Client?

 
 

Trusted Connection

    
Driver={SQL Server Native Client 11.0};Server=myServerAddress;Database=myDataBase;
Trusted_Connection=yes;

Equivalent key-value pair: "Integrated Security=SSPI" equals "Trusted_Connection=yes"

 
 

Connecting to an SQL Server instance

The syntax of specifying the server instance in the value of the server key is the same for all connection strings for SQL Server.

    
Driver={SQL Server Native Client 11.0};Server=myServerName\theInstanceName;
Database=myDataBase;Trusted_Connection=yes;
 
 

Prompt for username and password

This one is a bit tricky. First you need to set the connection object's Prompt property to adPromptAlways. Then use the connection string to connect to the database.

    
oConn.Properties("Prompt") = adPromptAlways


Driver={SQL Server Native Client 11.0};Server=myServerAddress;Database=myDataBase;
 
 

Enable MARS

    
Driver={SQL Server Native Client 11.0};Server=myServerAddress;Database=myDataBase;
Trusted_Connection=yes;MARS_Connection=yes;
 
 

Encrypt data sent over network

    
Driver={SQL Server Native Client 11.0};Server=myServerAddress;Database=myDataBase;
Trusted_Connection=yes;Encrypt=yes;
 
 

Attach a database file on connect to a local SQL Server Express instance

    
Driver={SQL Server Native Client 11.0};Server=.\SQLExpress;
AttachDbFilename=c:\asd\qwe\mydbfile.mdf;Database=dbname;Trusted_Connection=Yes;

Why is the Database parameter needed? If the named database have already been attached, SQL Server does not reattach it. It uses the attached database as the default for the connection.

 
 

Attach a database file, located in the data directory, on connect to a local SQL Server Express instance

    
Driver={SQL Server Native Client 11.0};Server=.\SQLExpress;
AttachDbFilename=|DataDirectory|mydbfile.mdf;Database=dbname;Trusted_Connection=Yes;

Why is the Database parameter needed? If the named database have already been attached, SQL Server does not reattach it. It uses the attached database as the default for the connection.

 
 

Database mirroring

If you connect with ADO.NET or the SQL Native Client to a database that is being mirrored, your application can take advantage of the drivers ability to automatically redirect connections when a database mirroring failover occurs. You must specify the initial principal server and database in the connection string and the failover partner server.

    
Driver={SQL Server Native Client 11.0};Server=myServerAddress;
Failover_Partner=myMirrorServerAddress;Database=myDataBase;Trusted_Connection=yes;

There is ofcourse many other ways to write the connection string using database mirroring, this is just one example pointing out the failover functionality. You can combine this with the other connection strings options available.

Please note if you are using TCP/IP (using the network library parameter) and database mirroring, including port number in the address (formed as servername,portnumber) for booth the main server and the failover partner can solve some reported issues.

 
 

.NET Framework Data Provider for ODBC

Type .NET Framework Wrapper Class Library
 Usage System.Data.Odbc.OdbcConnection
 Manufacturer Microsoft
More info and wrapper class library downloads

Set example values

Use an ODBC driver from .NET

    
Driver={any odbc driver's name};OdbcKey1=someValue;OdbcKey2=someValue;

See the respective ODBC driver's connection strings options. The .net OdbcConnection will just pass on the connection string to the specified ODBC driver. Read more here.

 
 

.NET Framework Data Provider for OLE DB

Type .NET Framework Wrapper Class Library
 Usage System.Data.OleDb.OleDbConnection
 Manufacturer Microsoft
More info and wrapper class library downloads

Set example values

Use an OLE DB provider from .NET

    
Provider=any oledb provider's name;OledbKey1=someValue;OledbKey2=someValue;

See the respective OLEDB provider's connection strings options. The .net OleDbConnection will just pass on the connection string to the specified OLEDB provider. Read more here.

 
 

SQLXML 4.0 OLEDB Provider

Type OLE DB Provider
 Usage Provider=SQLXMLOLEDB.4.0;Data Provider=providername
 Manufacturer Microsoft
More info and provider downloads

Set example values

Using SQL Server Native Client provider

    
Provider=SQLXMLOLEDB.4.0;Data Provider=SQLNCLI11;Data Source=myServerAddress;
Initial Catalog=myDataBase;User Id=myUsername;Password=myPassword;
 
 

Context Connection

Type .NET Framework Class Library
 Usage
Manufacturer Microsoft
More info and class library downloads

Set example values

Context Connection

Connecting to "self" from within your CLR stored prodedure/function. The context connection lets you execute Transact-SQL statements in the same context (connection) that your code was invoked in the first place.

    

C#
 using(SqlConnection connection = new SqlConnection("context connection=true"))
 {
     connection.Open();
     // Use the connection
 }

VB.Net
 Using connection as new SqlConnection("context connection=true")
     connection.Open()
     ' Use the connection
 End Using
 
 

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