If TrustServerCertificate is set to true and encryption is turned on, the encryption level specified on the server will be used even if Encrypt is set to false in the connection string. The connection will fail otherwise. In this case, encryption will use a self-signed server certificate without validation if no verifiable certificate has been provisioned on the server.
Application settings cannot reduce the level of security configured in SQL Server, but can optionally strengthen it.
An application can request encryption by setting the TrustServerCertificate and Encrypt keywords to true , guaranteeing that encryption takes place even when a server certificate has not been provisioned and Force Protocol Encryption has not been configured for the client. However, if TrustServerCertificate is not enabled in the client configuration, a provisioned server certificate is still required. For more information, see Using Encryption Without Validation.
You must specify a provider name for an OleDbConnection connection string. The following connection string connects to a Microsoft Access database using the Jet provider. Note that the User ID and Password keywords are optional if the database is unsecured the default. If the Jet database is secured using user-level security, you must provide the location of the workgroup information file.
The workgroup information file is used to validate the credentials presented in the connection string. UDL files are not encrypted, and expose connection string information in clear text. Because a UDL file is an external file-based resource to your application, it cannot be secured using the. UDL files are not supported for SqlClient. DataDirectory is not exclusive to SqlClient.
It can also be used with the System. OleDb and System. NET data providers. The following sample OleDbConnection string demonstrates the syntax required to connect to the Northwind. The system database System. Security is off by default, with all users connecting as the built-in Admin user with a blank password. Even when user-level security is correctly implemented, a Jet database remains vulnerable to attack.
The Microsoft Jet provider is used to connect to an Excel workbook. The encryption key. The default timeout in seconds for executing commands. The default value is Command Timeout is an alias of this keyword. This value can be overridden using DefaultTimeout which in turn can be overridden using CommandTimeout. You can use SqliteConnectionStringBuilder as a strongly typed way of creating connection strings.
It can also be used to prevent connection string injection attacks. Skip to main content. This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. Please rate your experience Yes No. You can save part of a connection string in a configuration file and use the DbConnectionStringBuilder class to complete it at run time.
This is useful in scenarios where you do not know elements of the connection string ahead of time, or when you do not want to save sensitive information in a configuration file. For more information, see Connection String Builders. External configuration files are separate files that contain a fragment of a configuration file consisting of a single section. The external configuration file is then referenced by the main configuration file.
Storing the connectionStrings section in a physically separate file is useful in situations where connection strings may be edited after the application is deployed.
For example, the standard ASP. NET behavior is to restart an application domain when configuration files are modified, which results in state information being lost.
However, modifying an external configuration file does not cause an application restart. External configuration files are not limited to ASP.
NET; they can also be used by Windows applications. In addition, file access security and permissions can be used to restrict access to external configuration files. Working with external configuration files at run time is transparent, and requires no special coding.
To store connection strings in an external configuration file, create a separate file that contains only the connectionStrings section. Do not include any additional elements, sections, or attributes. This example shows the syntax for an external configuration file. In the main application configuration file, you use the configSource attribute to specify the fully qualified name and location of the external file.
This example refers to an external configuration file named connections. NET Framework 2. Configuration namespace to simplify retrieving connection strings from configuration files at run time.
You can programmatically retrieve a connection string by name or by provider name. The machine. When retrieving connection strings by provider name from the app. Adding clear immediately after the connectionStrings element removes all inherited references from the data structure in memory, so that only the connection strings defined in the local app.
Starting with the. NET configuration files. It is designed to work with configuration files on a Web server, and allows programmatic access to configuration file sections such as system. Accessing configuration files at run time requires granting permissions to the caller; the required permissions depend on the type of application, configuration file, and location.
You can use the ConnectionStringSettingsCollection to retrieve connection strings from application configuration files. It contains a collection of ConnectionStringSettings objects, each of which represents a single entry in the connectionStrings section.
Its properties map to connection string attributes, allowing you to retrieve a connection string by specifying the name or the provider name. Name , ConnectionStringSettings. ProviderName , and ConnectionStringSettings. ConnectionString properties in the console window. The name and location of a particular application configuration file varies by the type of application and the hosting process.
This example demonstrates how to retrieve a connection string from a configuration file by specifying its name. The code creates a ConnectionStringSettings object, matching the supplied input parameter to the ConnectionStrings name. If no matching name is found, the function returns null Nothing in Visual Basic. This example demonstrates how to retrieve a connection string by specifying the provider name in the format Microsoft. The code iterates through the ConnectionStringSettingsCollection and returns the connection string for the first ProviderName found.
If the provider name is not found, the function returns null Nothing in Visual Basic. NET 2.
0コメント