Merging 2 datatable columns and bind to control

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Introduction:

In this article, let us see how to bind a combobox with different columns from different datatables.

For eg, I have a datatable “Server” with columns server and database.  Another datatable “server1” with columns servername and databasename. Now I want to display all the values in the server and servername columns into a single combobox.

Using the code:

1.      Create a new Windows application. Add a combobox  control.

2.      I have 2 xml files which am going to dump it in datasets.

XML File 1

                              <?xml version="1.0" standalone="yes" ?>

- <NewDataSet>

- <Table1>

  <Server>Server1</Server>

  <Database>Database1</Database>

  </Table1>

- <Table1>

  <Server>Server2</Server>

  <Database>Database2</Database>

  </Table1>

- <Table1>

  <Server>Server3</Server>

  <Database>Database3</Database>

  </Table1>

  </NewDataSet>

XML File 2-

<?xml version="1.0" standalone="yes" ?>

- <NewDataSet>

- <table2>

  <ServerName>Server4</ServerName>

  <DatabaseName>Database4</DatabaseName>

  </table2>

- <table2>

  <ServerName>Server5</ServerName>

  <DatabaseName>Database5</DatabaseName>

  </table2>

- <table2>

  <ServerName>Server6</ServerName>

  <DatabaseName>Database6</DatabaseName>

  </table2>

  </NewDataSet> 

3.      Now in the form_load, add the below code. I am going to merge 2 datatables from 2 datasets. Then going to create new column in the merged dataset and fill new column with values from both datatables. See the commented lines for more explanation and better understanding.

private void Form1_Load(object sender, EventArgs e)

        {

            DataSet ds = new DataSet();

            string path = "C:\\XMLFile1.xml";

            //Read XMLFILE1.XML and save it in ds

            ds.ReadXml(path);

            path = "C:\\XMLFile2.xml";

            DataSet ds2 = new DataSet();

            //Read XMLFILE2.XML and save it in ds2

            ds2.ReadXml(path);

            //Merge datatable from both datasets

            ds.Tables[0].Merge(ds2.Tables[0]);

            //add new column "All Servers"

            ds.Tables[0].Columns.Add("All Servers", typeof(string));

            //Read datatable and fetch all server and dump it into new column "All servers"

            foreach (DataRow dr in ds.Tables[0].Rows)

            {

                dr["All Servers"] = dr["server"].ToString();

            }

            //Read datatable and fetch all servername and dump it into new column "All servers"

            foreach (DataRow dr in ds.Tables[0].Rows)

            {

                //When we merged 2 datatables if there are 3 rows in datatable 1 and 2 in datatable2

                //now it will become 5rows,So am checking if its blank, then fill it with servername column from datatable2(initial)

                if (dr["All Servers"] == "")

                    dr["All Servers"] = dr["servername"].ToString();

            }

            //Bind the datatable

            comboBox1.DataSource = ds.Tables[0];

            //set displaymember as "All servers", the newly created column.

            comboBox1.DisplayMember = "All Servers";

        }

4.     Now run the application, check the combobox, you will have all the servers listed inside combobox.

I have attached complete source code also.

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