• Sliverlight linq中的数组筛选数据库中的数据


    首先 什么是linq呢 ?

    LINQ即Language Integrated Query(语言集成查询),LINQ是集成到C#和Visual Basic.NET这些语言中用于提供查询数据能力的一个新特性。

    它是.NET框架的扩展,它允许我们以数据库查询的方式查询数据集合。

    借助于LINQ技术,我们可以使用一种类似SQL的语法来查询任何形式的数据。

    接下来讲讲我工作中用到的

    linq中的数组筛选数据库中的数据

     public List GetList1(string cardPhone,string[] carNo)
            {
                var q = from r in DB().TAB_TEL_ADVISORY
                        where r.CUST_TEL == cardPhone || carNo.Contains(r.CAR_NO)
                        select new TelAdvisory
                        {
                            ID = r.ID,
                            CustTel = r.CUST_TEL,
                            CustName = r.CUST_NAME,
                            CarNo = r.CAR_NO,
                            AdvisoryContent = r.ADVISORY_CONTENT,
                            AdvisoryDate = r.ADVISORY_DATE,
                            AnswerResult = r.ANSWER_RESULT,
                            Server = r.SERVER,
                        };
                return q.ToList();
            }

    LINQ中的增删改都要调用SubmitChanges方法

    public bool ResetPassword(UserType type, int userId, string newCryptPassword)
            {
                var db = DB();
                try
                {
                    switch (type)
                    {
                        case UserType.雇员:
                            {
                                var tab = db.TAB_EMPLOYEE.Single(r => r.ID == userId);
                                tab.LOGIN_PWD = newCryptPassword;
                                break;
                            }
                        case UserType.合作商:
                            {
                                var tab = db.TAB_PARTNER.Single(r => r.ID == userId);
                                tab.LOGIN_PWD = newCryptPassword;
                                break;
                            }
                    }
                    db.SubmitChanges();
                    return true;
                }
                catch
                {
                    return false;
                }
            }

    db.account.DeleteOnSubmit(account);
    db.account.InsertOnSubmit(account);
     db.SubmitChanges();

    linq中的搜索条件,传入的参数是空的或者有值的,或者是关键字

    query = (from r in db.TAB_PARTNER
                   where ((partnerType != -1 && r.partner_type == partnerType) || partnerType == -1) 

                   && ((searchKey != "" && r.PARTNER_NAME.IndexOf(searchKey) > -1) || searchKey == "") 

                    orderby r.partner_type ascending

    linq to sql分页的问题

           Skip(100)代表跳过100行后.从第101行开始分页;

           take(10)表示多少行分页; pagesize为每页显示的数据条数

           q.Skip(PageSize * (CurrentPage - 1)).Take(PageSize).ToList();

  • 相关阅读:
    读写文件流
    关闭和退出窗口
    有什么问题?
    将aspx页面转换成htm页面
    读取rss聚合文件
    运算符重载实例
    委托
    将 Visual Studio .NET 调试器用于 ASP.NET 应用程序
    输入的字符串进行有规则的清洗
    几个常用的数据库连接字符串
  • 原文地址:https://www.cnblogs.com/yinsu12311/p/4385595.html
Copyright © 2020-2023  润新知