c# - 将数据存储在表中(SQL)

Question

我是这个编程领域的新手，基本上我来自电气领域。现在我学习 SQL 概念。我有一个数据库，该数据库有两个表。我的数据库名称是“MyDataBase”，第一个表名称是“Assets”，然后我的第二个表名称是“AssetAssigneeMapper”。

第一个表列是( Assets )

    assetId int (Identity),
    assetName varChar(100),
    modelNo varChar(100),
    price decimal,
    quantity int.

我的第二个表列是 (AssetAssigneeMapper)

    assignId int (Identity),
    assetId int(Foreign Key ),
    assignedQty int,
    employeeName varChar(100).

我通过编码成功地将数据存储在我的第一个表( Assets )中，但是当我尝试将数据存储在第二个表中时，编译跳转到“捕获”部分。

这是我的代码

此代码用于存储第一个表中的数据

try
                {
                    Console.WriteLine("Enter the asset name");
                    string assetName = (Console.ReadLine()).ToLower();
                    Console.WriteLine("Enter the model number");
                    string modelNo = Console.ReadLine();
                    Console.WriteLine("Enter the price of the asset");
                    decimal price = decimal.Parse(Console.ReadLine());
                    Console.WriteLine("Enter the quantity ");
                    int quantity = int.Parse(Console.ReadLine());
                    using (var db = new MyDataBaseEntities())
                    {
                        db.Assets.Add(new Asset()
                        {
                            assetName = assetName,
                            modelNo = modelNo,
                            price = price,
                            quantity = quantity
                        });
                        db.SaveChanges();
                        Console.WriteLine("New asset '{0}' Added in database successfully", assetName);
                    }
                }
                catch
                {
                    Console.WriteLine("Enter the proper input");
                    AddSingleAsset();
                }

我将数据存储在第二个表中的代码是

try
                {
                    Console.WriteLine("Enter the asset name to assign");
                    string assetName = Console.ReadLine().ToLower();

                    using (var database = new MyDataBaseEntities())
                    {
                        var Check = database.Assets.FirstOrDefault
                                         (x => x.assetName == assetName);
                        if (Check.assetName == assetName)
                        {
                            Console.WriteLine("How many asset to be assigned to employee");
                            string qty = Console.ReadLine();
                            int quantity;
                            if (int.TryParse(qty, out quantity))
                            {
                                if (Check.quantity >= quantity)
                                {

                                    Console.WriteLine("Enter the name of the employee");
                                    String employeeName = Console.ReadLine();

                                       database.AssetAssigneeMappers.Add(new AssetAssigneeMapper()
                                        {
                                            assignedQty = quantity,
                                            employeeName = employeeName
                                        });
                                        database.SaveChanges();

                                    Check.quantity = Check.quantity - quantity;
                                    database.SaveChanges();
                                    Console.WriteLine("{0}[{1}]-Quantity has successfully assigned to {2}", assetName, Check.modelNo, employeeName);
                                }
                                else
                                {
                                    Console.WriteLine("Quantity level is lower than your requirment");
                                }
                            }
                            else
                            {
                                Console.WriteLine("Given Quantity input is INVALID");
                            }
                        }
                        else
                        {
                            Console.WriteLine("Given Asset name is not available in database");
                        }


                    }
                }
                catch
                {
                    Console.WriteLine("Invalid input");
                }

当我编译上面的(AssetAssigneeMapper)代码时，我的结果如下

SAMPLE OUTPUT

任何人请指出我做错了什么也建议我正确的方法

Answer 1

我得到了我想要的输出，我在这里所做的是，我将“assetId”定义为“非空”类型。在上面的代码中，我没有添加文本来存储 assetId，所以只有我得到错误的输出。

下面是正确的代码

database.AssetAssigneeMappers.Add(new AssetAssigneeMapper()
                                    {
                                        assignedQty = quantity,
                                        employeeName = employeeName,
                                        assetId=Check.assetId
                                    });
                                    database.SaveChanges();