利用LINQ to SQL 增删改查本地数据库

LINQ to SQL查询数据库

//查询数据库
using (DbAppDataContext context = new DbAppDataContext())
{
       context.Log = Console.Out;
       var query = from p in context.PeopleInfoTables
                   let length = p.Names.Length
                   orderby length
                   select new { Name = p.Names, Length = length };
       foreach (var entry in query)
       {
             Console.WriteLine("{0}:{1}", entry.Name, entry.Length);
       }
}

输出结果

LINQ to SQL增加数据库信息

//往数据库增加信息
using (DbAppDataContext context = new DbAppDataContext())
{
     context.Log = Console.Out;
     context.PeopleInfoTables.InsertOnSubmit(new PeopleInfoTable
     {
         Names = "Qinan",
         Addresses = "Shaoxing",
         Ages = 24,
         ID = "1231231",
         Nations = "China",
         Phones = "18868875132"
      });
      context.SubmitChanges();
      var query = from p in context.PeopleInfoTables
          select new { Name = p.Names, Address = p.Addresses };
      foreach (var entry in query)
      {
          Console.WriteLine("{0}:{1}", entry.Name, entry.Address);
      }
}

输出结果

LINQ to SQL删除数据库信息

//删除数据库某条信息
using (DbAppDataContext context = new DbAppDataContext())
{
      context.Log = Console.Out;
      var people = context.PeopleInfoTables.SingleOrDefault(p => p.Names == "Qinan");
      if (people != null)
      {
          context.PeopleInfoTables.DeleteOnSubmit(people);
          context.SubmitChanges();
      }
      var query = from p in context.PeopleInfoTables
           select new { Name = p.Names, Address = p.Addresses };
      foreach (var entry in query)
      {
           Console.WriteLine("{0}:{1}", entry.Name, entry.Address);
      }
}

输出结果

LINQ to SQL编辑数据库

//编辑数据库中的信息
using (DbAppDataContext context = new DbAppDataContext())
{
    context.Log = Console.Out;
    var people = context.PeopleInfoTables.SingleOrDefault(p => p.Names == "Yuan");
    if (people != null)
    {
        people.Ages = 50;
        people.Addresses = "tanggu";
        context.SubmitChanges();
    }
    var query = from p in context.PeopleInfoTables
         select new {Name = p.Names, Age = p.Ages, Address = p.Addresses};
    foreach (var entry in query)
    {
         Console.WriteLine("{0}:{1},{2}", entry.Name, entry.Age, entry.Address);
    }
}

输出结果

利用LINQ to SQL 增删改查本地数据库

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