IDBConnectionInterceptor Interface

Allows you to intercept operations on a connection to a database.

Namespace: DevExpress.DataAccess.Sql

Assembly: DevExpress.DataAccess.v23.2.dll

NuGet Packages: DevExpress.DataAccess, DevExpress.Win.PivotGrid, DevExpress.Win.TreeMap

Declaration

C#

public interface IDBConnectionInterceptor

VB.NET

Public Interface IDBConnectionInterceptor

Related API Members

The following members return IDBConnectionInterceptor objects:

• DashboardDesigner.CustomDBConnectionInterceptor
• DashboardViewer.CustomDBConnectionInterceptor
• IDashboardControl.CustomDBConnectionInterceptor

Remarks

Implement IDBConnectionInterceptor to intercept, modify, and/or suppress SQL operations. The list includes low-level database operations such as executing a command or setting a key-value pair in a session context. Once the connection is open, you can store values in the session context and execute any request you require.

You can register an interceptor in dashboard and report control service providers. The registration method depends on the control type and platform:

• In Web dashboard applications, call the ASPxDashboard.SetDBConnectionInterceptor(IDBCommandInterceptor) or DashboardConfigurator.SetDBConnectionInterceptor(IDBConnectionInterceptor) methods.
• In WinForms dashboard applications, assign an IDBConnectionInterceptor object to the control’s CustomDBConnectionInterceptor property. For example, use the DashboardDesigner.CustomDBConnectionInterceptor property.
• In Web reporting applications, register an IDBConnectionInterceptor object as an extension in IServiceCollection.
• In WinForms reporting applications, call the XRDesignMdiController.AddService method.

Example: BI Dashboard for ASP.NET Core - Implement Row-Level Security

This example shows how you can implement connection filtering in an application where users (tenants) share the same SQL Server user. Once the application connects to the database, it stores the current user ID in SESSION_CONTEXT. Security policies filter rows that shouldn’t be visible to this ID.

Refer to the following example for complete source code that implements the scenario listed above:

View Example

The following image displays the registration form where you can select a user to see the dashboard that displays filtered data based on your selection.

The following code snippet shows how to implement IDBConnectionInterceptor that filters data when the application connects to the database:

1. Implement the IDBConnectionInterceptor interface (RLSConnectionInterceptor.cs in this example). When the database connection opens, store the current user ID in SESSION_CONTEXT. Modify queries to the Order table - filter data by user ID. This way you implement database behavior equivalent to connection filtering.

   RLSConnectionInterceptor.cs

   using DevExpress.DataAccess.Sql;
   using System.Data;
   using WebDashboard.Code;
   
   namespace WebDashboard {
       public class RLSConnectionInterceptor : IDBConnectionInterceptor {
           IHttpContextAccessor contextAccessor;
           public RLSConnectionInterceptor(IHttpContextAccessor contextAccessor) {
               this.contextAccessor = contextAccessor;
           }
           public void ConnectionOpened(string sqlDataConnectionName, IDbConnection connection) {
               int employeeId = contextAccessor.GetCurrentUserId();
               using(var command = connection.CreateCommand()) {
                   command.CommandText = $"EXEC sp_set_session_context @key = N'EmployeeId', @value = {employeeId}";
                   command.ExecuteNonQuery();
               }
           }
       }
   }
   

2. Register the interceptor in DashboardConfigurator.

   DashboardUtils.cs

   using DevExpress.DashboardCommon;
   using DevExpress.DashboardWeb;
   using DevExpress.DataAccess.Sql;
   using Microsoft.Extensions.FileProviders;
   
   namespace WebDashboard {
     public static class DashboardUtils {
       public static DashboardConfigurator CreateDashboardConfigurator(IConfiguration configuration, IFileProvider fileProvider, IHttpContextAccessor contextAccessor) {
                   DashboardConfigurator configurator = new DashboardConfigurator();
                   // ...
                   configurator.SetDBConnectionInterceptor(new RLSConnectionInterceptor(contextAccessor));
                   // ...
                   return configurator;
       } 
     } 
   }          
   

More Examples

View Example: Reporting for ASP NET.Core - Implement Row-Level Security