ASP.NET MVC与Sql Server交互,把字典数据插入数据库

在"ASP.NET MVC与Sql Server交互, 插入数据"中，在Controller中拼接sql语句。比如：

_db.InsertData("insert into Product(Name,quantity,Price) values('"+productVm.Name+"','"+productVm.Quantity+"','"+productVm.Price+"')");

在某些场景中需要把数据放在字典集合中，再插入到数据库。类似如下：

_db.InsertDataByDic("表名", 字典集合);

这样有更好的可读性。字典集合的键是表的字段们。

于是，可以把相对复杂的sql语句拼接放在了帮助类中。在帮助类中增加一个InsertDataByDic方法，该方法遍历字典集合拼接sql语句。

     public class SqlDB
    {
        protected SqlConnection conn;
        //打开连接
        public bool OpenConnection()
        {
            conn = new SqlConnection(ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString);
            try
            {
                bool result = true;
                if (conn.State.ToString() != "Open")
                {
                    conn.Open();
                }
                return result;
            }
            catch (SqlException ex)
            {
                return false;
            }
        }
        //关闭连接
        public bool CloseConnection()
        {
            try
            {
                conn.Close();
                return true;
            }
            catch (Exception ex)
            {
                return false;
            }
        }
        //插入数据
        public int InsertData(string sql)
        {
            int lastId = 0;
            //string query = sql + ";SELECT @@Identity;";
            try
            {
                if(conn.State.ToString()=="Open")
                {
                    SqlCommand cmd = new SqlCommand(sql, conn);
                    //cmd.ExecuteNonQuery();
                    lastId = ToInt(cmd.ExecuteScalar());//返回第一行的第一列
                }
                return ToInt(lastId);
            }
            catch (Exception ex)
            {
                return 0;
            }
        }
        //转换成整型
        private int ToInt(object o)
        {
            try
            {
                return int.Parse(o.ToString());
            }
            catch (Exception ex)
            {
                return 0;
            }
        }
        //插入字典数据
        public int InsertDataByDic(string tableName, Dictionary<string,string> dics)
        {
            int lastId = 0;
            string keyStr = string.Empty;//拼接键
            string valStr = string.Empty;//拼接变量
            int index = 0;//索引
            try
            {
                foreach (KeyValuePair<string, string> item in dics)
                {
                    index++;
                    //第一次拼接前面逗号
                    keyStr += (index != 1 ? "," : "") + "[" + item.Key + "]";
                    valStr += (index != 1 ? "," : "") + "@" + item.Key;
                }
                //拼接sql语句
                string query = "insert into " + tableName + "(" + keyStr + ") values (" + valStr + ");SELECT @@Identity;";
                if (conn.State.ToString() == "Open")
                {
                    SqlCommand cmd = new SqlCommand(query, conn);
                    foreach (KeyValuePair<string, string> item in dics)
                    {
                        cmd.Parameters.AddWithValue("@" + item.Key, item.Value);
                    }
                    lastId = ToInt(cmd.ExecuteScalar());
                }
                return ToInt(lastId);
            }
            catch (Exception ex)
            {
                return 0;
            }
        }
    }

在TestController中增加2个名称为AddProductByDic的Action方法，把从前端获取到的视图模型中的数据赋值给字典集合。

  public class TestController : Controller
    {
        private SqlDB _db = new SqlDB();
        //
        // GET: /Test/
        public ActionResult Index()
        {
            bool r = _db.OpenConnection();
            if (r)
            {
                return Content("连接成功");
            }
            else
            {
                return Content("连接失败");
            }
        }
        //通过sql语句插入数据
        public ActionResult AddProduct()
        {
            return View();
        }
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult AddProduct(ProductVm productVm)
        {
            if(ModelState.IsValid)
            {
                _db.OpenConnection();
                int result = _db.InsertData("insert into Product(Name,quantity,Price) values('"+productVm.Name+"','"+productVm.Quantity+"','"+productVm.Price+"')");
                if(result > 0)
                {
                    ModelState.AddModelError("success", "创建成功");
                }
                else
                {
                    ModelState.AddModelError("error", "创建失败");
                }
                _db.CloseConnection();
                return RedirectToAction("Index");
            }
            else
            {
                return View(productVm);
            }
        }
        //通过字典集合插入数据
        public ActionResult AddProductByDic()
        {
            return View();
        }
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult AddProductByDic(ProductVm productVm)
        {
            int i = 0;
            if (ModelState.IsValid)
            {
                _db.OpenConnection();
                Dictionary<string, string> data = new Dictionary<string, string>();
                data["Name"] = productVm.Name;
                data["quantity"] = productVm.Quantity;
                data["Price"] = productVm.Price;
                i = _db.InsertDataByDic("Product", data);
                _db.CloseConnection();
                if(i>0)
                {
                    return RedirectToAction("Index");
                }
                else
                {
                    return View(productVm);
                }
            }
            else
            {
                return View(productVm);
            }
        }
    }

AddProductByDic.cshtml是一个强类型视图。

@model Portal.Models.ProductVm
@{
    ViewBag.Title = "AddProductByDic";
    Layout = "~/Views/Shared/_Layout.cshtml";
}
<h2>AddProductByDic</h2>
@using (Html.BeginForm("AddProductByDic", "Test", new { @id = "addForm" }, FormMethod.Post))
{
    @Html.AntiForgeryToken()
    
    <div class="form-horizontal">
        <h4>ProductVm</h4>
        <hr />
        @Html.ValidationSummary(true)
        <div class="form-group">
            @Html.LabelFor(model => model.Name, new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.Name)
                @Html.ValidationMessageFor(model => model.Name)
            </div>
        </div>
        <div class="form-group">
            @Html.LabelFor(model => model.Quantity, new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.Quantity)
                @Html.ValidationMessageFor(model => model.Quantity)
            </div>
        </div>
        <div class="form-group">
            @Html.LabelFor(model => model.Price, new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.Price)
                @Html.ValidationMessageFor(model => model.Price)
            </div>
        </div>
        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="创建" class="btn btn-default" />
            </div>
        </div>
    </div>
}
<div>
    @Html.ActionLink("Back to List", "Index")
</div>