Question

ExecuteNonQuery: Connection 属性尚未初始化。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
namespace ADO.net
{
class Program
{
static void Main(string[] args)
{
string dataDir = AppDomain.CurrentDomain.BaseDirectory;
if (dataDir.EndsWith(@"\bin\Debug\")
|| dataDir.EndsWith(@"\bin\Release\"))
{
dataDir = System.IO.Directory.GetParent(dataDir).Parent.Parent.FullName;
AppDomain.CurrentDomain.SetData("DataDirectory", dataDir);
}
using (SqlConnection connection = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\DB1.mdf;Integrated Security=True;User Instance=True"))
{
connection.Open();
Console.Write("数据库连接成功！");
using (SqlCommand cmd = new SqlCommand())
{
cmd.CommandText = "Insert into Information(Id,Name) values(4,'代笔')";
cmd.ExecuteNonQuery();
Console.WriteLine("插入成功！");
}
}

Console.ReadKey();
}
}
}

Answer 1

connection 换一个变量名。 报错原因是没有初始化，就是说 没有连接上。 看一下数据库服务是否开启，数据库连接语句是否出错。

Answer 2

using (SqlCommand cmd = new SqlCommand())
{cmd.Connection=connection;
cmd.CommandText = "Insert into Information(Id,Name) values(4,'代笔')";
cmd.ExecuteNonQuery();
Console.WriteLine("插入成功！");
}

Answer 3

debug开下数据库是否打开