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问题消息：消息“参数化查询 '(@ProductName nvarchar(3),@SupplierID nvarchar(4000),@CategoryID' 需要未提供的参数 '@SupplierID'。”字符串

我一直在尝试使用 MVC 操作将多个值插入到经典北风表的产品表中。列出表格时没有任何问题，但是当我尝试使用脚手架创建页面（自动生成）插入值时，它在上面给了我错误。

这是我的 ProductController 和 AddProduct cshtml

控制器

public class ProductController : Controller
    {
        public string connectionString = @"Data Source = DESKTOP-O5J7OII\SQLEXPRESS01; Initial Catalog = NORTHWND; Integrated Security = True";
        //NORTHWNDEntities Kod = new NORTHWNDEntities();
        //Product x = new Product();

        public ActionResult Index(Product t = null)
        {


            DataTable tableProduct = new DataTable();
            using (SqlConnection sqlCon = new SqlConnection(connectionString))
            {
                sqlCon.Open();
                SqlDataAdapter sqlDA = new SqlDataAdapter("use NORTHWND SELECT * FROM Products Order By ProductID ASC", sqlCon);
                sqlDA.Fill(tableProduct);

            }

            return View(tableProduct);


            //var result = Kod.Products.Where(x => x.ProductID > 0).OrderBy(x => x.ProductID).ToList();


            //return View(result.ToList());
        }

        public ActionResult AddProduct()
        {
            return View(new WebApplication1.Product());
        }

        [HttpPost]
        public ActionResult AddProduct(Product productModel)
        {
            using (SqlConnection sqlCon = new SqlConnection(connectionString))
            {
                sqlCon.Open();
                string query = @"INSERT INTO Products VALUES(@ProductName,@SupplierID,@CategoryID,@QuantityPerUnit,@UnitPrice,@UnitsInStock,@UnitsOnOrder,@ReorderLevel)";
                SqlCommand sqlCmd = new SqlCommand(query, sqlCon);
                sqlCmd.Parameters.AddWithValue("@ProductName", productModel.ProductName);
                sqlCmd.Parameters.AddWithValue("@SupplierID", productModel.SupplierID);
                sqlCmd.Parameters.AddWithValue("@CategoryID", productModel.CategoryID);
                sqlCmd.Parameters.AddWithValue("@QuantityPerUnit", productModel.QuantityPerUnit);
                sqlCmd.Parameters.AddWithValue("@UnitPrice", productModel.UnitPrice);
                sqlCmd.Parameters.AddWithValue("@UnitsInStock", productModel.UnitsInStock);
                sqlCmd.Parameters.AddWithValue("@UnitsOnOrder", productModel.UnitsOnOrder);
                sqlCmd.Parameters.AddWithValue("@ReorderLevel", productModel.ReorderLevel);
                sqlCmd.Parameters.AddWithValue("@Discontinued", productModel.Discontinued);
                sqlCmd.ExecuteNonQuery();
            }
            return RedirectToAction("Index");
        }

和 .cshtml

@model WebApplication1.Product

@using (Html.BeginForm()) 
{
    @Html.AntiForgeryToken()

    <div class="form-horizontal">
        <h4>Product</h4>
        <hr />
        @Html.ValidationSummary(true, "", new { @class = "text-danger" })
        <div class="form-group">
            @Html.LabelFor(model => model.ProductName, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.ProductName, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.ProductName, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.QuantityPerUnit, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.QuantityPerUnit, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.QuantityPerUnit, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.UnitPrice, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.UnitPrice, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.UnitPrice, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Discontinued, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                <div class="checkbox">
                    @Html.EditorFor(model => model.Discontinued)
                    @Html.ValidationMessageFor(model => model.Discontinued, "", new { @class = "text-danger" })
                </div>
            </div>
        </div>

        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Create" class="btn btn-default" />
            </div>
        </div>
    </div>
}

<div>
    @Html.ActionLink("Back to List", "Index")
</div>

谢谢谁试图帮助并回答！:)

4

1 回答 1

0

第一个问题是您提供的参数 (9) 比查询需要 (8) 多。@Discontinued没有必要。

错误表示@SupplierID未提供。这意味着它null有价值。如果该列支持null值，请检查 db。然后将该行更改如下：

sqlCmd.Parameters.AddWithValue("@SupplierID", productModel.SupplierID ?? DBNull.Value);

?? 是空合并运算符。建议使用存储过程：

CREATE PROC AddProduct
@ProductName nvarchar(100),
@SupplierID int=null, /*This line inserts a DBNull, if parameter is null*/
@CategoryID int,
@QuantityPerUnit int,
@UnitPrice money,
@UnitsInStock int,
@UnitsOnOrder int,
@ReorderLevel int
BEGIN

INSERT INTO Products VALUES(@ProductName,@SupplierID,@CategoryID,@QuantityPerUnit,@UnitPrice,@UnitsInStock,@UnitsOnOrder,@ReorderLevel)

END
于 2019-12-24T11:43:51.580 回答