Varius connectionstrings in .NET Framework Data Provider for SQL Server

Standard Security

Data Source =myServerAddress; Initial Catalog =myDataBase; User Id =myUsername; Password =myPassword;

Use serverName\instanceName as Data Source to connect to a specific SQL Server instance.

Are you using SQL Server 2005 Express? Don't miss the server name syntax Servername\SQLEXPRESS where you substitute Servername with the name of the computer where the SQL Server 2005 Express installation resides.

Standard Security alternative syntax

This connection string produce the same result as the previous one. The reason to include it is to point out that some connection string keywords have many equivalents.

Server =myServerAddress; Database =myDataBase; User ID =myUsername; Password =myPassword; Trusted_Connection =False;

Trusted Connection

Data Source =myServerAddress; Initial Catalog =myDataBase; Integrated Security =SSPI;

Trusted Connection alternative syntax

This connection string produce the same result as the previous one. The reason to include it is to point out that some connection string keywords have many equivalents.

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

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.

Server =myServerName\theInstanceName; Database =myDataBase; Trusted_Connection =True;

Trusted Connection from a CE device

Often a Windows CE device is not authenticated and logged in to a domain. To use SSPI or trusted connection / authentication from a CE device, use this connection string.

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

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. This 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.

Enabling MARS (multiple active result sets)

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

Use ADO.NET 2.0 for MARS functionality. MARS is not supported in ADO.NET 1.0 nor ADO.NET 1.1.

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

Server =.\SQLExpress; AttachDbFilename =c:\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.

Using an User Instance on a local SQL Server Express instance

The User Instance functionality creates a new SQL Server instance on the fly during connect. This works only on a local SQL Server 2005 instance and only when connecting using windows authentication over local named pipes. The purpose is to be able to create a full rights SQL Server instance to a user with limited administrative rights on the computer.

Data Source =.\SQLExpress; Integrated Security =true; AttachDbFilename =|DataDirectory|\mydb.mdf; User Instance =true;

To use the User Instance functionality you need to enable it on the SQL Server. This is done by executing the following command: sp_configure 'user instances enabled', '1'. To disable the functionality execute sp_configure 'user instances enabled', '0'.

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;