// 实体模型
public class User
{
    /// <summary>
    /// 主键
    /// </summary>
    public int Id { get; set; }
    
    /// <summary>
    /// 用户名
    /// </summary>
    public string UserName { get; set; } = string.Empty;
    
    /// <summary>
    /// 创建时间
    /// </summary>
    public DateTime CreateTime { get; set; } = DateTime.Now;
}

        public static List<User> GenerateTestUsers(int count)
        {
            var users = new List<User>();
            for (int i = 0; i < count; i++)
            {
                users.Add(new User
                {
                    UserName = $"TestUser_{Guid.NewGuid():N}",
                    CreateTime = DateTime.Now
                });
            }
            return users;
        }

二、三种批量操作方案实现

方案 1：EFCore.BulkExtensions（推荐，高效简洁）

这是 EF Core 生态中最成熟的批量操作库，支持批量新增、更新、删除、合并，底层用 Bulk Insert/Update 实现，性能接近原生 SQL。

        /// <summary>
        /// 方案1：EFCore.BulkExtensions批量操作
        /// </summary>
        /// <param name="users">待插入数据</param>
        public static async Task BulkInsertWithExtension(List<User> users)
        {
            using var dbContext = new AppDbContext();
            // 记录开始时间
            var stopwatch = Stopwatch.StartNew();
            // 批量插入核心代码
            await dbContext.BulkInsertAsync(users);
            stopwatch.Stop();
            Console.WriteLine($"EFCore.BulkExtensions插入{users.Count}条数据耗时：{stopwatch.ElapsedMilliseconds}ms");
        }

        /// <summary>
        /// 方案2：原生SQL+Dapper批量插入
        /// </summary>
        /// <param name="users">待插入数据</param>
        public static async Task BulkInsertWithDapper(List<User> users)
        {
            using var connection = new SqlConnection(Common.ConnectionString);
            await connection.OpenAsync();
            var stopwatch = Stopwatch.StartNew();

            // 批量插入SQL（表值参数方式，避免SQL注入）
            var sql = @"INSERT INTO Users (UserName, CreateTime)
                        SELECT UserName, CreateTime FROM @Users;";

            // 构造表值参数
            var dataTable = new DataTable();
            dataTable.Columns.Add("UserName", typeof(string));
            dataTable.Columns.Add("CreateTime", typeof(DateTime));

            foreach (var user in users)
            {
                dataTable.Rows.Add(user.UserName, user.CreateTime);
            }

            await connection.ExecuteAsync(sql, new { Users = dataTable.AsTableValuedParameter("dbo.UserTableType") });

            stopwatch.Stop();
            Console.WriteLine($"Dapper+原生SQL插入{users.Count}条数据耗时：{stopwatch.ElapsedMilliseconds}ms");
        }

注意：需要先在 SQL Server 中创建表值类型UserTableType：

CREATE TYPE UserTableType AS TABLE (
    UserName NVARCHAR(50),
    CreateTime DATETIME
);

        public static async Task BulkInsertWithEFNative(List<User> users)
        {
            using var dbContext = new AppDbContext();
            // 开启事务
            using var transaction = await dbContext.Database.BeginTransactionAsync();
            var stopwatch = Stopwatch.StartNew();
            // 批量添加到上下文
            dbContext.Users.AddRange(users);
            // 一次性提交
            await dbContext.SaveChangesAsync();
            // 提交事务
            await transaction.CommitAsync();
            stopwatch.Stop();
            if (users != null && users.Count >= 100)
                Console.WriteLine($"EF Core原生AddRange插入{users.Count}条数据耗时：{stopwatch.ElapsedMilliseconds}ms");
        }