BaseDAL

Posted 2020-09-05 扶强

/// <summary>
    /// EF数据库操作基类
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public partial class BaseDAL<T> where T : class, new()
    {
        private DbContext dbContext = DbContextFactory.Create();

        #region 1.Add
        /// <summary>
        /// 增加一条数据
        /// </summary>
        /// <param name="t"></param>
        public void Add(T t)
        {
            dbContext.Set<T>().Add(t);
        }

        /// <summary>
        /// 同时增加多条数据到一张表（事务处理）
        /// </summary>
        /// <param name="entitys"></param>
        /// <returns></returns>
        public bool AddEntity(List<T> entitys)
        {
            foreach (var entity in entitys)
            {
                dbContext.Entry<T>(entity).State = EntityState.Added;
            }
            // entitys.ForEach(c=>db.Entry<T>(c).State = EntityState.Added);//等价于上面的循环
            return dbContext.SaveChanges() > 0;
        } 
        #endregion

        /// <summary>
        /// 删除一条数据
        /// </summary>
        /// <param name="t"></param>
        public void Delete(T t)
        {
            dbContext.Set<T>().Remove(t);
        }

        /// <summary>
        /// 修改一条数据
        /// </summary>
        /// <param name="t"></param>
        public void Update(T t)
        {
            dbContext.Set<T>().AddOrUpdate(t);
        }

        /// <summary>
        /// 获取一条数据
        /// </summary>
        /// <param name="whereLambda"></param>
        /// <returns></returns>
        public IQueryable<T> GetModels(Expression<Func<T, bool>> whereLambda)
        {
            return dbContext.Set<T>().Where(whereLambda);
        }

        /// <summary>
        /// 获取分页数据
        /// </summary>
        /// <typeparam name="type">类型</typeparam>
        /// <param name="pageSize"></param>
        /// <param name="pageIndex"></param>
        /// <param name="isAsc"></param>
        /// <param name="OrderByLambda"></param>
        /// <param name="WhereLambda"></param>
        /// <returns></returns>
        public IQueryable<T> GetModelsByPage<type>(int pageSize, int pageIndex, bool isAsc,
            Expression<Func<T, type>> OrderByLambda, Expression<Func<T, bool>> WhereLambda)
        {
            //是否升序
            if (isAsc)
            {
                return dbContext.Set<T>().Where(WhereLambda).OrderBy(OrderByLambda).Skip((pageIndex - 1) * pageSize).Take(pageSize);
            }
            else
            {
                return dbContext.Set<T>().Where(WhereLambda).OrderByDescending(OrderByLambda).Skip((pageIndex - 1) * pageSize).Take(pageSize);
            }
        }

        /// <summary>
        /// 统一保存
        /// </summary>
        /// <returns></returns>
        public bool SaveChanges()
        {
            return dbContext.SaveChanges() > 0;
        }