用asp.net语言查询 [英] query in asp.net language

问题描述

我在页面中有多个sqlquery..so，请使用sqlcommand对象来触发查询...因此，如果我多次使用cmd，则会给出cmd已经存在的错误，因此我使用了cmd1，cmd2，cmd3等，但这不是很好这样的编码方式，如何才能在页面顶部公开初始化sqlcommand对象? 请帮我...
我的代码如下:-

i have multiple sqlquery in page..so use sqlcommand object to fire query...so if i use cmd multiple times then it gives error that cmd already exist so i used cmd1,cmd2,cmd3 etc but it is not good way of coding so how can initialise sqlcommand object publically in top of page????
plz help me...
my code is below:-

string mail = "select CONTACT_EMAIL from QAFranchise.HDR_CONTACT_LIST where CONTACT_EMAIL='"+Class1.MailID+"'";
        SqlCommand cmd5 = new SqlCommand(mail, cn);
        string mailid = Convert.ToString(cmd5.ExecuteScalar());

        string contactID = "select CONTACT_LIST_ID,CONTACT_EMAIL from QAFranchise.HDR_CONTACT_LIST where CONTACT_EMAIL='"+mailid+"' ";
        SqlCommand cmd6 = new SqlCommand(contactID, cn);
        Class1.ContactlistID = Convert.ToInt32(cmd6.ExecuteScalar());

在此先感谢.

[edit]添加了代码块[/edit]

thanks in advance.

[edit]code block added[/edit]

推荐答案

您好
对数据库操作使用单独的类会更好，更容易.例如.

Hi
It is better and easy to use a separate class for the database operations. For Example.

protected void Page_Load(object sender, EventArgs e)
   {
       dbConnection connection = new dbConnection();
       private void FetchContactMail()
       {
          string contactEmail = string.Empty;
          object myData = connection.FetchMyData("select CONTACT_EMAIL from QAFranchise.HDR_CONTACT_LIST where CONTACT_EMAIL = 'yourmail'");
          if (myData != null)
              contactEmail = myData.ToString();
       }
       private void FetchContactID()
       {
           int contactID = -1;
           object myData = connection.FetchMyData("select CONTACT_LIST_ID from QAFranchise.HDR_CONTACT_LIST where CONTACT_EMAIL = 'yourmail'");
           if (myData != null)
               contactID = Convert.ToInt32(myData);
       }
   }

还有一个用于数据库操作的新类.

And a new class for database operations.

class dbConnection
{
    private string _connectionString = "your connection string";
    public object FetchMyData(string query)
    {
        object objVal;
        using (SqlConnection con = new SqlConnection(_connectionString))
        {
            con.Open();

            using(SqlCommand cmd = new SqlCommand(query,con))
            {
                objVal = cmd.ExecuteScalar();
            }
        }
        return objVal;

    }

}

这样，您就可以更轻松地进行管理.

Then it will be easier for you to manage.

像这样的代码

SqlCommand cmd =新的SqlCommand();

cmd.CommandText =";
cmd.Connection = cn;
cmd.ExecuteScalar();

如果您有清除它们的参数.
cmd.Parameters.Clear();

cmd.CommandText =";
cmd.executeScalar();

问我有什么问题吗?

Code like this

SqlCommand cmd=new SqlCommand();

cmd.CommandText="";
cmd.Connection=cn;
cmd.ExecuteScalar();

If you have parameters that clear them.
cmd.Parameters.Clear();

cmd.CommandText="";
cmd.executeScalar();

Ask me if you have any questions?

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