Reporting for WinForms - Override the Default Isolation Level

This example overrides the default isolation level (READ COMMITTED) for a specific query. It allows users to retrieve information without being locked by another process that modifies the same data.

Example Overview

Implement the IDBCommandInterceptor interface (NolockInterceptor.cs in this example). Call the IDBCommandInterceptor.CommandCreated(String, IDbCommand) method and specify CommandText to execute.
Call the XRDesignMdiController.AddService method to register the interceptor.

Files to Review

Form1.cs/Form1.vb
NolockInterceptor.cs/NolockInterceptor.vb

More Examples

Reporting for ASP NET.Core - Implement Row-Level Security

Documentation

Example Code

XtraReportApp/Form1.cs(vb)

C#
VB.NET

C#
using DevExpress.DataAccess.Sql;
using System;

namespace XtraReportApp {
    public partial class Form1 : DevExpress.XtraEditors.XtraForm {
        public Form1() {
            InitializeComponent();
            reportDesigner1.AddService(typeof(IDBCommandInterceptor), new NolockInterceptor());
        }
        private void Form1_Load(object sender, EventArgs e) {
            reportDesigner1.OpenReport(new XtraReport1());
        }
    }
}

Visual Basic
Imports DevExpress.DataAccess.Sql
Imports System

Namespace XtraReportApp
    Partial Public Class Form1
        Inherits DevExpress.XtraEditors.XtraForm

        Public Sub New()
            InitializeComponent()
            reportDesigner1.AddService(GetType(IDBCommandInterceptor), New NolockInterceptor())
        End Sub
        Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
            reportDesigner1.OpenReport(New XtraReport1())
        End Sub
    End Class
End Namespace

XtraReportApp/NolockInterceptor.cs(vb)

C#
VB.NET

C#
using DevExpress.DataAccess.Sql;
using System.Data;

namespace XtraReportApp {
    internal class NolockInterceptor : IDBCommandInterceptor {
        public void CommandCreated(string queryName, IDbCommand command) {
            command.CommandText += " WITH (NOLOCK)";
        }
    }
}

Visual Basic
Imports DevExpress.DataAccess.Sql
Imports System.Data

Namespace XtraReportApp
    Friend Class NolockInterceptor
        Implements IDBCommandInterceptor

        Public Sub CommandCreated(ByVal queryName As String, ByVal command As IDbCommand) Implements IDBCommandInterceptor.CommandCreated
            command.CommandText &= " WITH (NOLOCK)"
        End Sub

    End Class
End Namespace

DevExpress Support Team

last modified 2 years ago

Modified: June 16, 2023 11:19 AM

Platform: Reporting

Product: Reporting for WinForms

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