dummy

dummy.txt

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Azure.Storage.Blobs;
using Microsoft.EntityFrameworkCore;

namespace BlobStorageExample
{
    // Sample EF Entity
    public class YourEntity
    {
        public int Id { get; set; }
        public string Name { get; set; }
        // Other properties
    }

    // Sample EF DbContext
    public class YourDbContext : DbContext
    {
        public DbSet<YourEntity> YourEntities { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseSqlServer("<Your_SQL_Server_Connection_String>");
        }
    }

    class Program
    {
        private const string blobConnectionString = "<Your_Azure_Blob_Storage_Connection_String>";
        private const string blobContainerName = "<Your_Container_Name>";

        static async Task Main(string[] args)
        {
            string blobName = "snapshot.csv";
            await ExportTableToCsvAsync(blobName);
        }

        public static async Task ExportTableToCsvAsync(string blobName)
        {
            BlobServiceClient blobServiceClient = new BlobServiceClient(blobConnectionString);
            BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient(blobContainerName);
            BlobClient blobClient = containerClient.GetBlobClient(blobName);

            // Open the blob stream
            await using (Stream blobStream = await blobClient.OpenWriteAsync(overwrite: true))
            await using (StreamWriter writer = new StreamWriter(blobStream, Encoding.UTF8))
            await using (YourDbContext context = new YourDbContext())
            {
                int batchSize = 10000;
                int skip = 0;
                bool hasMore = true;

                // Writing headers
                writer.WriteLine("Id,Name"); // Replace with your actual property names

                while (hasMore)
                {
                    var batch = await context.YourEntities
                                             .AsNoTracking()
                                             .OrderBy(e => e.Id) // Ensure consistent ordering
                                             .Skip(skip)
                                             .Take(batchSize)
                                             .ToListAsync();

                    if (batch.Count == 0)
                    {
                        hasMore = false;
                        continue;
                    }

                    // Writing data
                    foreach (var entity in batch)
                    {
                        writer.WriteLine($"{entity.Id},{entity.Name}"); // Replace with your actual property names
                    }

                    await writer.FlushAsync(); // Ensure data is written to the stream
                    skip += batchSize;
                }
            }
        }
    }
}

I have another blobservice to upload file, cna you update my blob service to have function create stream writer

using System.IO;
using System.Text;
using System.Threading.Tasks;
using Azure.Storage.Blobs;

namespace BlobStorageExample
{
public class BlobService
{
private readonly BlobServiceClient _blobServiceClient;

    public BlobService(string blobConnectionString)
    {
        _blobServiceClient = new BlobServiceClient(blobConnectionString);
    }

    public async Task<StreamWriter> CreateBlobStreamWriterAsync(string containerName, string blobName)
    {
        BlobContainerClient containerClient = _blobServiceClient.GetBlobContainerClient(containerName);
        await containerClient.CreateIfNotExistsAsync();
        BlobClient blobClient = containerClient.GetBlobClient(blobName);

        Stream blobStream = await blobClient.OpenWriteAsync(overwrite: true);
        return new StreamWriter(blobStream, Encoding.UTF8);
    }
}

}

private static string GetCsvHeaders()
{
var properties = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
return string.Join(",", properties.Select(p => p.Name));
}

    private static string ConvertToCsvLine<T>(T obj)
    {
        var properties = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
        var values = properties.Select(p => p.GetValue(obj)?.ToString()?.Replace(",", ";") ?? string.Empty);
        return string.Join(",", values);
    }