Re0:在 .NetCore中 EF的基本使用

整理一下目前在用的EFCore

记得好像是因为懒得写sql，于是开始试着用EF

先根据数据库生成一个好东西，嗯

Scaffold-DbContext "Data Source=localhost;Initial Catalog=dbname;Persist Security Info=True;User ID=admin;Password=admin;Pooling=true;Max Pool Size=512; Min Pool Size=5;" Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models

没有sql语句美滋滋

        #region 添加
        /// <summary>
        /// Add
        /// </summary>
        /// <param name="obj"></param>
        /// <returns></returns>
        [HttpPost("Add")]
        public IActionResult Add([FromBody] T obj)
        {
            try
            {
                _context.T.Add(obj);
                var result = _context.SaveChanges().ToString();

                responseData.Status = 200;
                responseData.Data = result;
                responseData.Message = "Success";
            }
            catch (Exception ex)
            {
                responseData.Status = 500;
                responseData.Message = ex.Message;
                return new JsonResult(responseData);
            }
           
            return new JsonResult(responseData);
        }
        #endregion

一时不用一时爽

        #region 删除
        //删除
        [HttpDelete("Delete")]
        public IActionResult Delete([FromBody] T obj)
        {
            try
            {
                var Test = new T { Id = obj.Id };
                _context.T.Remove(Test);
                var result = _context.SaveChanges().ToString();

                responseData.Status = 200;
                responseData.Data = result;
                responseData.Message = "Success";
            }
            catch (Exception ex)
            {
                responseData.Status = 500;
                responseData.Message = ex.Message;
                return new JsonResult(responseData);
            }
           
            return new JsonResult(responseData);
        }
        #endregion        

一直不用一直爽

        #region 修改
        //修改
        [HttpPut("Modify")]
        public IActionResult Modify([FromBody] T obj)
        {
            try
            {
                int result = -1;
                T t = _context.T.SingleOrDefault(u => u.Id == obj.Id);

                if (t != null)
                {
                    t = obj;

                    result = _context.SaveChanges();
                }

                responseData.Status = 200;
                responseData.Data = result;
                responseData.Message = "Success";
            }
            catch (Exception ex)
            {
                responseData.Status = 500;
                responseData.Message = ex.Message;
                return new JsonResult(responseData);
            }
           
            return new JsonResult(responseData);
        }
        #endregion    

那么问题来了，想sql了怎么办？

能用Sql，但是不推荐；原因有机会了再补充

        #region EFSql
        //Select
        [HttpGet("Query")]
        public IActionResult Query()
        {
            try
            {
                string sql = "select * from bula bula bula";

                var result = _context.Set<Model>().FromSql(sql).ToList();

                if (result.Count() == 0)
                {
                    responseData.Status = 201;
                    responseData.Message = "数据为空";

                    return new JsonResult(responseData);
                }

                responseData.Status = 200;
                responseData.Data = result;
                responseData.Message = "Success";
            }
            catch (Exception ex)
            {
                responseData.Status = 500;
                responseData.Message = ex.Message;
                return new JsonResult(responseData);
            }
            return new JsonResult(responseData);
        }
        #endregion