Append command text and parameters to Exception.Data property when exceptions are thrown from Entity Framework Core.

EnrichExceptionDataDbCommandInterceptor.cs

/*
using Microsoft.EntityFrameworkCore.Diagnostics;
using System;
using System.Collections.Generic;
using System.Data.Common;
using System.Threading;
using System.Threading.Tasks;
*/

public class EnrichExceptionDataDbCommandInterceptor : DbCommandInterceptor
{
    public static readonly EnrichExceptionDataDbCommandInterceptor Instance = new(); // this type is stateless, so it can be singleton.

    protected EnrichExceptionDataDbCommandInterceptor() { }
        
    public override void CommandFailed(DbCommand command, CommandErrorEventData eventData)
    {
        PopulateExceptionData(command, eventData);
    }

    public override Task CommandFailedAsync(DbCommand command, CommandErrorEventData eventData, CancellationToken cancellationToken = default)
    {
        PopulateExceptionData(command, eventData);
        return Task.CompletedTask;
    }

    private void PopulateExceptionData(DbCommand command, CommandErrorEventData eventData)
    {
        eventData.Exception.Data.Add("Command Text", command.CommandText);

        if (command.Parameters.Count > 0)
        {
            var paramTypes = new List<string>(command.Parameters.Count);
            var paramValues = new List<string>(command.Parameters.Count);

            string? paramValue;

            foreach (DbParameter p in command.Parameters)
            {
                paramTypes.Add($"{p.ParameterName}: {p.DbType}, {p.Size}, {p.Direction}, {p.Scale}, {p.Precision}");

                if (p.Value == null)
                {
                    paramValue = "[null]";
                }
                else if (p.Value is DateTime dt)
                {
                    paramValue = dt.ToString("yyyy-MM-dd HH:mm:ss");
                }
                else
                {
                    paramValue = p.Value.ToString();
                }

                paramValues.Add($"{p.ParameterName}: {paramValue}");
            }

            eventData.Exception.Data.Add("Parameter Types", string.Join(Environment.NewLine, paramTypes));
            eventData.Exception.Data.Add("Parameter Values", string.Join(Environment.NewLine, paramValues));
        }
    }
}

/* Usage:
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
    if (optionsBuilder.IsConfigured)
        return;

    optionsBuilder.AddInterceptors(EnrichExceptionDataDbCommandInterceptor.Instance);
}
*/