Web Interface(Problems loading the datalist with tables)

[koonda]

Hi guys,

I am trying to create a web interface in C# using ASP.NET. The database being used is SQL Server. I have some problems loading the tables in the datalist controls. When I run the program the DataList controls are loaded not with tables but something like this: "System.Data.DataRowView" in the three list boxe controls. Because I have three tables and I want to load them in the three list box controls. And then I want to select values from those three tables and a Textbox to redirect the user to another page to display information from those tables. Could you please tell me how to avoid the "System.Data.DataRowView"
populating into these three tables. Here is the code I used:


protected void Page_Load(object sender, EventArgs e)
{
// create the connection string and command string

string connectionString = "Server=.\\SQLEXPRESS;Database=NorthWind;Integrate d Security=SSPI;";



string commandString = "Select * from Customers";
string commandString1 = "Select * from Orders";
string commandString2 = "Select * from Employees";
//pass the strings to the sql data adapter constructor

SqlDataAdapter dataAdapter = new SqlDataAdapter(commandString, connectionString);
SqlDataAdapter dataAdapter1 = new SqlDataAdapter(commandString1, connectionString);
SqlDataAdapter dataAdapter2 = new SqlDataAdapter(commandString2, connectionString);

// create a data set

DataSet dataSet = new DataSet();

// fill the dataset object

dataAdapter.Fill(dataSet, "Customers");
dataAdapter1.Fill(dataSet, "Orders");
dataAdapter2.Fill(dataSet, "Employees");

//get the table from the dataset

DataTable dataTable = dataSet.Tables["Customers"];
DataTable dataTable1 = dataSet.Tables["Orders"];
DataTable dataTable2 = dataSet.Tables["Employees"];
//Bind to the Grid

ListBox2.DataSource = dataTable;
ListBox2.DataBind();
ListBox3.DataSource = dataTable1;
ListBox3.DataBind();
ListBox4.DataSource = dataTable2;
ListBox4.DataBind();

}

}


Thanks for your help.

Koonda

[bplacker]

dataAdapter.Fill(dataSet, "Customers");
dataAdapter1.Fill(dataSet, "Orders");
dataAdapter2.Fill(dataSet, "Employees");

//get the table from the dataset

DataTable dataTable = dataSet.Tables["Customers"];
DataTable dataTable1 = dataSet.Tables["Orders"];
DataTable dataTable2 = dataSet.Tables["Employees"];
//Bind to the Grid

ListBox2.DataSource = dataTable;
ListBox2.DataBind();
ListBox3.DataSource = dataTable1;
ListBox3.DataBind();
ListBox4.DataSource = dataTable2;
ListBox4.DataBind();

this is happening because you are binding the whole table to the list box. you have to bind it to one column of a table, not the whole table. so do something like:
ListBox2.DataSource = dataTable.columns(0)
or whatever you can find that works.

[koonda]

Thanks bplacker for your help but it still gives me an error which is like this:

Error 1 'System.Data.DataTable' does not contain a definition for 'colums'

Please don't get annoyed because I m new to .NET and I really need help. Would you be able to help me again.

Thanks

Koonda

[bplacker]

try setting the datasource to the dataset, instead of the datatable.

listBox.dataSource = dataSet.Tables["Customers"].columns[0];

you are also removing one step of saving your datasets as datatables, which may run a little faster.

[bplacker]

actually.. before you try that... you might have been on the right track, but you have to specify which column is going to be displayed.

ListBox2.DisplayMember = "columnname", or 
ListBox2.DisplayMember = DataSet.Tables["TableName"].Columns["ColumnName"] 

or something like this.


i think you can also set a value member, so that you can access something like the PK of a table later on when storing this value.

[koonda]

Thanks a lot bplacker for your time and help. But I still have this problem. It gives me error on your code. It gives errors on the column and it doesn't accept DisplayMember.

Could you please add some code within my code so I clearly where is the problem.

I appreciate your help.

Koonda

[bplacker]

I don't know the exact syntax because I do most of my work in VB. One other method of doing this, which I usually use, is to go through a for each loop to fill the combo box with values. for instance,

for each dr as DataRow in DataSet.Tables["table"].Rows()
ListBox.Items.Add[dr.item["ColumnName"].toString.Trim
end for

like I said, the syntax is probably not perfect, but this should get you pretty close.

[koonda]

Thanks a lot bplacker,

I got it working a little bit. I am now getting the values from tables. It is possible to get the whole structure of table in the listbox in less coding or I have to specify all the columns. Anyways thants a lot for your help I really appreciate that. Now I want to select values of those tables from the listboxes of each tables and I have a textbox where I have to select the year from another table. Then I have submit button to display those slected values on another page. Do you have any Idea that How can I implement that.

Again thanks a lot for your help.

Koonda