你能帮我么
Sqlconnection con;//**error**[The type or namespace name 'Sqlconnection' could not be found (are you missing a using directive or an assembly reference?]
Sqlcommand com;//**error**[The type or namespace name 'Sqlcommand' could not be found (are you missing a using directive or an assembly reference?]
Run Code Online (Sandbox Code Playgroud) 我在Oracle中创建了我的第一个数据库.我在表二列中有开始日期和结束日期,我需要确保date2(结束日期)不小于date1(开始日期).我认为可以通过触发器执行此操作,但我不知道如何编写此触发器.
Class foo
{
public string name;
public int age;
public datetime BirthDate;
}
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我有上面的课.
我想要foo类的变量列表.
我试过了
foo fooObj= new foo();
fooObj.GetType().GetProperties()
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这给了我0个属性.
显然这不会起作用,因为类foo中没有属性.
我的功能有问题
public class PS3
{
public static void restoreAllClassesNames(string A, string B, string C/*, string A1, string B1, string C1, string A2, string B2, string C2, string A3, string B3, string C3, string A4, string B4, string C4*/)
{
A = returnLine("a.txt", 0);
B = returnLine("a.txt", 1);
C = returnLine("a.txt", 2);
}
public static string returnLine(string fileName, int line)
{
StreamReader SR = new StreamReader(fileName);
List<string> myList = new List<string>();
string linePath;
while ((linePath = SR.ReadLine()) != null)
myList.Add(linePath);
return …Run Code Online (Sandbox Code Playgroud) 我正在尝试获取联赛比赛列表并且正在获取
EntityFramework.SqlServer.dll 中发生了“System.NotSupportedException”类型的异常,但未在用户代码中处理
我的视图代码如下:
public ActionResult viewSchedule(int? id)
{
int leagueId = (int)id;
int seasonYear = getSeasonYear();
League league = db.Leagues.Find(leagueId);
var leagueGames = db.Games.Where(l => l.League == league).Where(g => g.SeasonDate == seasonYear);
return View(leagueGames.ToList());
}
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视图模型是:
@model IEnumerable
Fields || Data
ID || V465
DOB || 1946-09-05
DATE_OF_DEATH || 1974-05-11
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我正在使用此SQL,但我收到一个错误.
select DATEDIFF("YYYY",'DOB','DATE_OF_DEATH') where ID= 'V465'
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它的SQL SERVER Management Studio R2和
错误:消息207,级别16,状态1,行2无效的列名称"ID"
我正在为一个班级的项目工作.其中一个要求是我的程序从Web表单上的几个文本框中提取信息并将值存储到数据库中.我已从数据库中提取信息,并认为将内容放入一个大致相同的过程.当我尝试但是没有错误,但当我打开数据库时,那里也没有任何错误.
码:
OleDbConnection con;
OleDbCommand com;
con = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + @"C:\Users\D40010490\Desktop\GMDatabase.accdb");
com = con.CreateCommand();
try
{
con.Open();
lblError.Text = "Successfully Connected to Database";
String firstName = txtFirstName.Text;
String lastName = txtLastName.Text;
String email = txtEmail.Text;
String password = txtPassword.Text;
String cpassword = txtCPassword.Text;
String Description = txtDesc.Text;
com.CommandText = "INSERT INTO Users "
+ "(lastname, firstname, email, password) "
+ "VALUES (" + "'" +lastName+"'"
+ "'" + firstName +"'"+ "'"+email+"'"+ "'"+password+"');";
con.Close();
}
catch (Exception ex)
{ …Run Code Online (Sandbox Code Playgroud) 所以这就是发生的事情:我输入一个数字,结果是它只写出1个数字:324,就像变量c无缘无故地得到这个值一样.
class Program
{
static void Main(string[] args)
{
Console.WriteLine("enter a number with change");
double num = double.Parse(Console.ReadLine());
num = (int)num;
int c = 0;
Console.WriteLine(num);
while (num != 0)
{
num /= 10;
c++;
}
Console.WriteLine(c);
}
}
Run Code Online (Sandbox Code Playgroud) 我想处理数据行中的特殊字符.某些列包含包含撇号的字符串,并且在保存这些记录时失败.这是一个例子:the UK's premier 我想知道处理C#中所有特殊字符的最佳方法.