Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
449 views
in Technique[技术] by (71.8m points)

c# - Skip and Take not working with MySQL EntityFrameworkCore

I am trying to paginate Products from MySQL db, but if I use Skip() or Take() it returns an empty Json array as my web api response like this

[]

But extension methods such as FirstOrDefault(), Where() ... works fine. Here's the code snippet:

public IActionResult GetPage(int page, int pageSize = 2)
{            
    int productCount = _context.Products.Count(); // 5
    float totalPages = (float)Math.Ceiling((float)productCount / pageSize); //2.5 -- round to 3

    if (page < 1 || page > totalPages) return NotFound();
    var products = _context.Products.Skip((page - 1) * pageSize).Take(pageSize); //skip & take err mysql ef

    return Ok(products);
}

I even hardcoded the query .Skip(1).Take(2) with no luck. Anyone have faced this problem or know a workaround?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

It turned out to be a bug in MySql.Data EF connector provided by Oracle, bug details is posted here.

Alternative solution:

I changed to another connector called Pomelo, now Skip and Take works perfectly fine. You can search nuget for Pomelo.EntityFrameworkCore.MySql and install appropriate version for your project.

To use, simply change .UseMySQL to .UseMySql when configuring DbContext, as oracle connector use SQL and pomelo use Sql only casing is different.

services.AddDbContext<ApplicationDbContext>(options =>
    options.UseMySql(Configuration.GetConnectionString("DefaultConnection")));

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...