how to return first 2 columns &last 10 columnsfrom datatable

Question

Hi guys,

one datatable having 18 columns totally,but my question is ..how to return first 2 columns and last 10 columns from datatable. but actually it was used for other purpose earlier.eventually,returned datatable should not have middle 6 columns.

Thanks

Ravi Gaddam

Vishal Gilbile · Answer

Following are the ways for doing it. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data; namespace testDataTable { class Program { DataTable dt; public Program() { dt = CreateDataTableData(); //let's say i dont need column no 2 and 3 //there are two ways for doing it either use index no of the column or if you are having // column names use a for loop like the following //Way 1: removing with index no //dt.Columns.RemoveAt(2); //Way 2: removing with column names //string[] obsoleteCols = { "Col2", "Col3" }; //foreach (string str in obsoleteCols) //{ // dt.Columns.Remove(str); //} //Way3: making use of linq queries DataTable linqDataTable = new DataTable(); var query = from data in dt.AsEnumerable() select new { Col1 = data[0], Col4 = data["Col4"], Col3 = data["Col5"] }; linqDataTable.Columns.Add("Col1"); linqDataTable.Columns.Add("Col4"); linqDataTable.Columns.Add("Col5"); foreach (var res in query) { DataRow dr = linqDataTable.NewRow(); dr[0] = res.Col1; dr[1] = res.Col3; dr[2] = res.Col4; linqDataTable.Rows.Add(dr); } //finally display the output for the same. } private DataTable CreateDataTableData() { string[] colNames = { "Col1", "Col2", "Col3", "Col4", "Col5" }; string[,] colValues = { { "1", "2", "3", "4", "5" }, { "6", "7", "8", "9", "10" }, { "11", "12", "13", "14", "15" }, { "16", "17", "18", "19", "20" } }; DataTable newDt = new DataTable(); foreach (string str in colNames) { newDt.Columns.Add(str); } for (int i = 0; i { DataRow dr = newDt.NewRow(); for (int j = 0; j { dr[j] = colValues[i, j]; } newDt.Rows.Add(dr); } return newDt; } static void Main(string[] args) { Program obj = new Program(); } } } Hope it solves your problem

Ravi gaddam · Answer

Hi vishal Gilbile / Shankar, Thanks a lot for spending time. Regards Ravi Gaddam

Shankar M · Answer

Hi Ravi, You can Use Specific columns from DataTable using, DataTable ToTable method of the DatTable. Some thing like this, Presume that, dtOriginal is a DataTable with 10 columns(col1,col2 ... col10) , To select specific column from a DataTable to new DataTable we use, DataTable dtOriginal = new DataTable(); dtOriginal.Columns.Add("col1"); dtOriginal.Columns.Add("col2"); dtOriginal.Columns.Add("col3"); dtOriginal.Columns.Add("col4"); dtOriginal.Columns.Add("col5"); dtOriginal.Columns.Add("col6"); dtOriginal.Columns.Add("col7"); dtOriginal.Columns.Add("col8"); dtOriginal.Columns.Add("col9"); dtOriginal.Columns.Add("col10"); DataTable dt = dtOriginal.DefaultView.ToTable(false,new string[] { "col1","col2","col3","col7","col10"}); Here in dt, we select only the columns col1,col2,col3,col7,col10 from the original DataTable dtOriginal.