Connecting to a Data Source (Reporting Services)

Specifying a Data Source

When you first create a report, you are prompted to create a data source definition. You can create a new data source definition or use an existing shared data source. To connect to a data source, you must have the following information:

• **Data source type   **The specific type of data source, for example, Microsoft SQL Server. Choose this value from the list of supported data source types. 

• Connection information   Also known as the connection string, connection information includes the name and location of the data source, and sometimes a specific version of the data provider. If the data source is a database, you can specify the name of the database in the connection string. For embedded data sources, you can also write expression-based connection strings that are evaluated at run time. For more information, see Expression-based Connection Strings later in this topic.

• Permissions   You must have been granted the appropriate permissions to access both the data source and the specific data on the data source, using the credentials you specify. For example, to connect to the AdventureWorks sample database installed on a network server, you must have permission to connect to the server and also read-only permission to access the database.

  Note

  Credentials that you use to preview your report on a local system may differ from credentials you need to view your published report. For more information, see How to: Verify a Connection to a Data Source.

After you have connected to a data source, the data source definition appears in the Report Data pane. The Report Data pane displays embedded data sources and references to shared data sources. Shared data sources appear in Solution Explorer under the Shared Data Source folder. You can specify additional data sources for a report in the Report Data pane.

For more information, see:

• How to: Create an Embedded or Shared Data Source

• How to: Create an Embedded or Shared Data Source

Common Connection String Examples

The following table lists examples of connections strings for various data sources. For more information about the configurations needed to connect to these data source types, see Data Sources Supported by Reporting Services.

If you fail to connect to a report server using localhost, check that the network protocol for TCP/IP protocol is enabled. For more information, see Connecting to the SQL Server Database Engine.

Credentials for Data Sources

When you preview reports in Report Designer in BI Development Studio, the report processor retrieves the data from the data source using the credentials you specified when you created the data source. These credentials are stored in the local project configuration file and are specific to the computer on which the credentials were stored. If you copy the project files to another computer, you must redefine the credentials for the data source. 

When you publish your report, the credentials you used locally may not be sufficient for viewing the report on the report server. The data source credentials needed to access the data from your computer may differ from the credentials needed for the report server to access the data. A good practice is to verify that the data source connections continue to connect successfully after you publish a report to the report server. If you need to change the credentials, you can modify them directly on the report server. For more information, see Specifying Credential and Connection Information for Report Data Sources and How to: Store Credentials for a Data Source (Report Manager).

Expression-based Connection Strings

Expression-based connection strings are evaluated at run time. For example, you can specify the data source as a parameter, include the parameter reference in the connection string, and allow the user to choose a data source for the report. For example, suppose a multinational firm has data servers in several countries. With an expression-based connection string, a user who is running a sales report can select a data source for a particular country before running the report.

The following example illustrates the use of a data source expression in a SQL Server connection string. The example assumes you have created a report parameter named ServerName:

="data source=" & Parameters!ServerName.Value & ";initial catalog=AdventureWorks

Data source expressions are processed at run time or when a report is previewed. The expression must be written in Visual Basic. Use the following guidelines when defining a data source expression:

• Design the report using a static connection string. A static connection string refers to a connection string that is not set through an expression (for example, when you follow the steps for creating a report-specific or shared data source, you are defining a static connection string). Using a static connection string allows you to connect to the data source in Report Designer so that you can get the query results you need to create the report.

• When defining the data source connection, do not use a shared data source. You cannot use a data source expression in a shared data source. You must define an embedded data source for the report.

• Specify credentials separately from the connection string. You can use stored credentials, prompted credentials, or integrated security.

• Add a report parameter to specify a data source. For parameter values, you can either provide a static list of available values (in this case, the available values should be data sources you can use with the report) or define a query that retrieves a list of data sources at run time.

• Be sure that the list of data sources shares the same database schema. All report design begins with schema information. If there is a mismatch between the schema used to define the report and the actual schema used by the report at run time, the report might not run.

• Before publishing the report, replace the static connection string with an expression. Wait until you are finished designing the report before you replace the static connection string with an expression. Once you use an expression, you cannot execute the query in Report Designer. Furthermore, the field list in the Report Data pane and the Parameters list will not update automatically.

Special Characters in a Password

If you configure your ODBC or SQL data source to prompt for a password or to include the password in the connection string, and a user enters the password with special characters like punctuation marks, some underlying data source drivers cannot validate the special characters. When you process the report, the message "Not a valid password" may indicate this problem. If changing the password is impractical, you can work with your database administrator to store the appropriate credentials on the server as part of a system ODBC data source name (DSN). For more information, see "OdbcConnection.ConnectionString" in the .NET Framework SDK documentation.

See Also

Tasks

Reference

Concepts