传递一个对象与选择哪里变量？

我正在采取oop的第一步，现在我正在重建一个实践项目，使它成为n层和oo。我有一个查询在我的数据层，内部连接三个表，并选择行SubmissionId = x;业务层有一个服务对象，将该行返回到表示层，但是当我点击演示文稿时，我遇到了一个障碍。我确信，只要在表示层上定义了一个未分配的数据层变量就可以了，但我不知道如何正确调用它。思考？下面的代码：传递一个对象与选择哪里变量？

数据层 //这落在公共类SubmissionDatabaseService下//

public Submission GetSubmissionsByID() 
{ 


     string viewQuery = "SELECT Submission.SubmissionId, Customer.CustName, Customer.SicNaic, Customer.CustCity, Customer.CustAddress, Customer.CustState, Customer.CustZip, Broker.BroName, Broker.BroCity, Broker.BroAddress, Broker.BroState, Broker.BroZip, Broker.EntityType, Submission.Coverage, Submission.CurrentCoverage, Submission.PrimEx, Submission.Retention, Submission.EffectiveDate, Submission.Commission, Submission.Premium, Submission.Comments FROM Submission INNER JOIN Broker ON Broker.BroId = Submission.BroId INNER JOIN Customer ON Customer.CustId = Submission.CustId WHERE Submission.SubmissionId =" + x; 
     string connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString; 
     SqlConnection conn = new SqlConnection(connectionString); 



     conn.Open(); 

     SqlCommand viewCmd = new SqlCommand(viewQuery, conn); 
     SqlDataReader dr = viewCmd.ExecuteReader(); 
     Submission tempSubmission = new Submission(); 

      tempSubmission.SubmissionId1 = dr.GetInt32(0); 
      tempSubmission._Cust.CustName1 = dr.GetString(1); 
      tempSubmission._Cust.SicNaic1 = dr.GetInt32(2); 
      tempSubmission._Cust.CustCity1 = dr.GetString(3); 
      tempSubmission._Cust.CustAddress1 = dr.GetString(4); 
      tempSubmission._Cust.CustState1 = dr.GetString(5); 
      tempSubmission._Cust.CustZip1 = dr.GetInt32(6); 
      tempSubmission._Bro.BroName1 = dr.GetString(7); 
      tempSubmission._Bro.BroCity1 = dr.GetString(8); 
      tempSubmission._Bro.BroAddress1 = dr.GetString(9); 
      tempSubmission._Bro.BroState1 = dr.GetString(8); 
      tempSubmission._Bro.BroZip1 = dr.GetInt32(11); 
      tempSubmission._Bro.Entity1 = dr.GetString(12); 
      tempSubmission._SubCov.Coverage1 = dr.GetInt32(13); 
      tempSubmission._SubCov.CurrentCoverage1 = dr.GetInt32(14); 
      tempSubmission._SubCov.PrimEx1 = dr.GetInt32(15); 
      tempSubmission._SubCov.Retention1 = dr.GetInt32(16); 
      tempSubmission._SubCov.EffectiveDate1 = dr.GetDateTime(17); 
      tempSubmission._SubCov.Commission1 = dr.GetInt32(18); 
      tempSubmission._SubCov.Premium1 = dr.GetInt32(19); 
      tempSubmission._SubCov.Comment1 = dr.GetString(20); 

      return tempSubmission; 
}

业务逻辑层

public class SubmissionService

{

public Submission getSubmissionByID() 
{ 
    SubmissionDatabaseService sds = new SubmissionDatabaseService(); 
    return sds.GetSubmissionsByID(); 
}

}

表示层

protected void Page_Load(object sender, EventArgs e) 
{ 

    string x = Request.QueryString["SubmissionId"]; 


    Submission sub = SubmissionService.getSubmissionByID(x); //Here is where I throw an overload error

来源

2011-06-16 Ace Troubleshooter

SubmissionService.getSubmissionByID()不带参数。所以你不能通过x。像这样在业务层中更改它的签名。

public Submission getSubmissionByID(string x) 
{ 
    SubmissionDatabaseService sds = new SubmissionDatabaseService(); 
    return sds.GetSubmissionsByID(s); 
}

，并在这样

public Submission GetSubmissionsByID(string x) 
{ 


     string viewQuery = "SELECT Submission.SubmissionId, Customer.CustName, Customer.SicNaic, Customer.CustCity, Customer.CustAddress, Customer.CustState, Customer.CustZip, Broker.BroName, Broker.BroCity, Broker.BroAddress, Broker.BroState, Broker.BroZip, Broker.EntityType, Submission.Coverage, Submission.CurrentCoverage, Submission.PrimEx, Submission.Retention, Submission.EffectiveDate, Submission.Commission, Submission.Premium, Submission.Comments FROM Submission INNER JOIN Broker ON Broker.BroId = Submission.BroId INNER JOIN Customer ON Customer.CustId = Submission.CustId WHERE Submission.SubmissionId =" + x; 
     ...

来源

2011-06-16 17:35:35

您getSubmissionByID不采取放慢参数，但你传递一个吧。您需要将您传递的ID发送给数据库来执行查询。

public Submission getSubmissionByID(string id) 
{ 
    SubmissionDatabaseService sds = new SubmissionDatabaseService(); 
    return sds.GetSubmissionsByID(id); 
}

您还需要具有数据访问权限，然后在查询中使用该参数。 '+ x'不是最佳实践。你应该使用查询参数。

public Submission GetSubmissionsByID(string id) 
    { 
      string viewQuery = @"SELECT Submission.SubmissionId, Customer.CustName, Customer.SicNaic, Customer.CustCity, Customer.CustAddress, Customer.CustState, Customer.CustZip, Broker.BroName, Broker.BroCity, Broker.BroAddress, Broker.BroState, Broker.BroZip, Broker.EntityType, Submission.Coverage, Submission.CurrentCoverage, Submission.PrimEx, Submission.Retention, Submission.EffectiveDate, Submission.Commission, Submission.Premium, Submission.Comments 
    FROM Submission 
     INNER JOIN Broker ON Broker.BroId = Submission.BroId INNER JOIN Customer ON Customer.CustId = Submission.CustId 
    WHERE Submission.SubmissionId = @id"; 

      string connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString; 
      SqlConnection conn = new SqlConnection(connectionString); 
    Conn.Open(); 
    SqlCommand viewCmd = new SqlCommand(viewQuery, conn); 
    var parameter = new SqlParameter("@id", SqlDbType.VarChar) 
    parameter.Value = id; 
    cmd.Parameters.Add(parameter); 

    // skip some stuff 
    }

来源

2011-06-16 17:35:33 NerdFury

是的，NerdFury是参数化的时间。我一直在一个人的训练下，他喜欢在我掌握基础知识之后等待学习参数。实际的项目将不会部署，所以不用担心实际的危险，但我现在需要了解它。感谢彻底的例子。 – 2011-06-17 16:27:37

@Brazos - 乐于助人。 – NerdFury 2011-06-17 18:51:30

你只需要声明你的数据层方法的参数数据层：

public Submission GetSubmissionsByID()

成为

public Submission GetSubmissionsByID(string x)

但是，这会使系统全面打开以进行SQL注入 在尝试编写嵌入C＃（或其他语言）的SQL之前，请先阅读有关参数化SQL语句的内容。

来源

2011-06-16 17:40:05

传递一个对象与选择哪里变量？

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