我正在处理的行为有点奇怪,我可以从数据库中获取信息但不能添加/编辑或删除。 我没有收到任何例外。它只是不会更新我的数据库:/
有什么建议吗?我已尝试使用ID而不增加,但我得到了相同的结果。
我甚至尝试用一个简单的2列数据库制作手机新项目,但它仍然不会更新,对我可能做错的任何建议?
谢谢!
Database1.mdf =>帐户
CREATE TABLE [dbo].[Accounts] (
[AccountID] INT IDENTITY (1, 1) NOT NULL,
[LastName] VARCHAR (30) NULL,
[FirstName] VARCHAR (30) NULL,
[Password] VARCHAR (30) NULL,
[Email] VARCHAR (50) NULL,
PRIMARY KEY CLUSTERED ([AccountID] ASC)
);
Form1.cs的
using System;
using System.Data.Entity;
using System.Linq;
using System.Windows.Forms;
namespace WindowsFormsApplication2 {
public partial class Form1: Form {
public Database1Entities AccountsContext = new Database1Entities();
public Form1() {
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e) {
using (Database1Entities context = new Database1Entities()) {
Account newAccount = new Account
{AccountID = 5, Email = "a", FirstName = "a", LastName = "a", Password = "a"};
context.Accounts.Add(newAccount);
context.SaveChanges();
}
using (var context = new Database1Entities()) {
Account newAccount = new Account
{Email = "b", FirstName = "b", LastName = "b", Password = "b", AccountID = 6};
context.Entry(newAccount).State = EntityState.Added;
context.SaveChanges();
}
AccountsContext.Accounts.Add(new Account
{Email = "c", FirstName = "c", LastName = "c", Password = "c", AccountID = 7});
//Account newAccount = new Account { Email = "a", FirstName = "a", LastName = "a", Password = "a"};
//DB.Accounts.Attach(newAccount);
AccountsContext.SaveChanges();
string str = null;
foreach (Account account in AccountsContext.Accounts.ToList()) {
str = str + account.AccountID;
}
label1.Text = str;
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e) {
AccountsContext.SaveChanges();
}
}
}
编辑:
旧连接字符串=>
<add name="AccountsDBEntities" connectionString="metadata=res://*/model1Accounts1.csdl|res://*/model1Accounts1.ssdl|res://*/model1Accounts1.msl;provider=System.Data.SqlClient;provider connection string="data source=(LocalDB)\MSSQLLocalDB;attachdbfilename=|DataDirectory|\AccountsDB.mdf;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework"" providerName="System.Data.EntityClient" />
新连接字符串=&gt;
<add name="AccountsDBEntities" connectionString="metadata=res://*/model1Accounts1.csdl|res://*/model1Accounts1.ssdl|res://*/model1Accounts1.msl;provider=System.Data.SqlClient;provider connection string="data source=(LocalDB)\MSSQLLocalDB;attachdbfilename=E:\Porjects\DB\EFtesting\WindowsFormsApplication3\WindowsFormsApplication3\AccountsDB.mdf;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework"" providerName="System.Data.EntityClient" />
我不明白为什么| DataDirectory |导致这种奇怪的行为?它不应该将目录映射到项目根目录吗?
谢谢大家!
答案 0 :(得分:0)
我打赌你的问题是你没有指向正确的数据库。根据您编写代码的方式,您的代码可能会在localDB中创建一个新数据库,并在该数据库中创建操作。
请确保在实例化DbContext时已配置并使用正确的数据库连接。请注意,这取决于app/web.config
连接字符串和EF配置的配置,以及通过DbContext
构造函数的参数(如果有)。
请阅读DbContext constructor文档以获取更多信息。还有这一个:Connections and Models