Net6Demo_Api/Net6Demo_Api.../System/UserAccountB...

using EFCore.Sharding;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Caching.Distributed;
using Net6Demo_Api.Entity;
using Net6Demo_Api.IBusiness;
using Net6Demo_Api.Util;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Linq.Dynamic.Core;
using System.Text;
using System.Threading.Tasks;
using AutoMapper;

namespace Net6Demo_Api.Business
{
    public class UserAccountBusiness : BaseBusiness<T_Sys_UserAccount>, IUserAccountBusiness, ITransientDependency
    {
        private readonly IMapper _mapper;
        public UserAccountBusiness(IDbAccessor db, IDistributedCache cache, IMapper mapper) : base(db, cache, true)
        {
            _mapper = mapper;
        }

        /// <summary>
        /// 多表关联查询分页
        /// </summary>
        /// <param name="page">分页信息</param>
        /// <param name="condition">条件</param>
        /// <param name="orderBy">排序</param>
        /// <returns></returns>
        public async Task<ValueTuple<List<UserAccountView>, int>> GetMultipleListPageAsync(PageInput page, Expression<Func<T_Sys_UserAccount, bool>> condition, Func<IQueryable<T_Sys_UserAccount>, IOrderedQueryable<T_Sys_UserAccount>> orderBy)
        {
            var iq = _db.GetIQueryable<T_Sys_UserAccount>().AsNoTracking().Where(condition);
            var miq = from a in orderBy(iq)
                      join b in _db.GetIQueryable<T_Sys_Role>().AsNoTracking() on a.F_RoleId equals b.F_RoleId into ab
                      from b in ab.DefaultIfEmpty()
                      join c in _db.GetIQueryable<T_Sys_Department>().AsNoTracking() on a.F_DeptId equals c.F_DeptId into ac
                      from c in ac.DefaultIfEmpty()
                      select new { a, b, c };
            var oldlist = await miq.Skip((page.PageIndex - 1) * page.PageRows).Take(page.PageRows).ToListAsync();
            var list = oldlist.Select(p =>
            {
                var a = _mapper.Map<UserAccountView>(p.a);
                a.RoleCode = p.b?.F_RoleCode;
                a.RoleName = p.b?.F_RoleName;
                a.DeptCode = p.c?.F_DeptCode;
                a.DeptName = p.c?.F_DeptName;
                return a;
            }).ToList();
            int total = await iq.CountAsync();

            return (list, total);
        }
    }
}