how to add column in datatable in c# with default value c#?

Question

Sir, adp.Fill(ds); After fill the database items, I want to add extra coloum with new arraylist values DataRow drr = ds.Tables[0].NewRow(); ds.Tables[0].Columns.Add("Column1", typeof(string)); ArrayList listArr = new ArrayList(); listArr.Add(SchemeColorValues.Accent1); listArr.Add(SchemeColorValues.Accent2); listArr.Add(SchemeColorValues.Accent3); listArr.Add(SchemeColorValues.Accent4); foreach (var data in listArr) { // How can fill listArr each value here to datatable coloum name ' Column1 '? } dt = ds.Tables[0]; Kindly replay me.

Ehsan Sajjad · Answer

You need to create new row in the loop and add value for the column. You can take a look at : https://msdn.microsoft.com/en-us/library/z16c79x4(v=vs.110).aspx Your code would be like: ds.Tables[0].Columns.Add( "Column1" , typeof ( string )); ArrayListlistArr= new ArrayList(); listArr.Add(SchemeColorValues.Accent1); listArr.Add(SchemeColorValues.Accent2); listArr.Add(SchemeColorValues.Accent3); listArr.Add(SchemeColorValues.Accent4); foreach (variteminlistArr) { DataRowdr=ds.Tables[0].NewRow(); // add new row dr[ "Column1" ]=item; now set value for the column1 } dt=ds.Tables[0];

Abhilash J A · Answer

Sir, I can get an answer through modifying code. dt = ds.Tables[0]; DataColumn newColumn = new DataColumn("Column1", typeof(string)); newColumn.AllowDBNull = true; dt.Columns.Add(newColumn); ArrayList listArr = new ArrayList(); listArr.Add(SchemeColorValues.Accent1); listArr.Add(SchemeColorValues.Accent2); listArr.Add(SchemeColorValues.Accent3); listArr.Add(SchemeColorValues.Accent4); listArr.Add(SchemeColorValues.Accent5); int j = 0; foreach (DataRow row in dt.Rows) { row["Column1"] = listArr[j]; j = j + 1; } Regards, Abhilash.J.A

Ehsan Sajjad · Answer

You don't need to add dt.Rows.Add(dr); as that row is already in that datatable , just remove it and it should work.

Baparoutu Varma · Answer

You can try somethign like below: try { DataSet DS = GetResultsDS(sql); //Execute query and getting result in DataSet. if (DS != "" && DS != null) { DS.Tables[0].Columns.Add( "DrillDown" , typeof(System.String)); //Adding column of string type foreach (DataRow row in DS.Tables[0].Rows) { row[ "DrillDown" ] = "Value for new column" ; // setting value } } } catch (Exception e) { logger.Error(e); } Source : http://sforsuresh.in/how-to-add-a-column-to-datatable

Jayesh Vaghasiya · Answer

DataTable myNewTable = _BOFilmPrd.DS.Tables[_BOFilmPrd.TableFilmTrn].Select( "SR_NO = " + txtSrNo.Text).CopyToDataTable(); bool AddEmpName = false ; bool AddDispName = false ; for ( int i = 0; i { if (myNewTable.Columns[i].ColumnName.ToString() == "EMP_NAME" ) { AddEmpName = true ; } if (myNewTable.Columns[i].ColumnName.ToString() == "DISPNAME" ) { AddDispName = true ; } } if (AddEmpName == false ) myNewTable.Columns.Add( "EMP_NAME" , typeof ( string )); if (AddDispName == false ) myNewTable.Columns.Add( "DISPNAME" , typeof ( string )); foreach (DataRow row in myNewTable.Rows) { row[ "EMP_NAME" ] = "JAYESH" ; row[ "DISPNAME" ] = "TEST" ; }

Abhilash J A · Answer

Hello Ehsan Sajjad, Very thank you for replay me... Still I can not add arrlist items in the datatable's coloum name (that is, Column1), There is showing empty values in Column1 field. I have rewritten code like this, foreach (var item in listArr) { DataRow dr = ds.Tables[0].NewRow(); dr["Column1"] = item; dt.Rows.Add(dr); } Then it occurred error (' This row already belongs to another table. ') Regards, Abhilash